I finished the challenge a few days ago. I have all the expansion packs and game packs (up to and including 'Get Famous', which came out during my attempt at the challenge) and decided to max every skill possible (except the minor skills) and complete every aspiration level possible in order to maximise my score.
POINTS
Skills maxed at level 10+ (I included Vampire Lore which maxes out at level 15) -> 28 skills * 10 points per skill = 280 points
Aspiration levels completed (counting 'mostly harmless', 'readily a parent' and 'prudent student' once each even though they each feature in multiple aspirations ) -> 33 levels * 5 points = 165 points
Completed on day 100 -> 1 point (could have done this earlier as I had at least 250k left after building the mansion, but I knew I'd get more points by finishing off maxing my skills)
No deductions for unpaid bills or critical social
Total points: 280 + 165 + 1 - 0 = 446 points
(Full info on skills maxed and aspiration levels achieved is at the end of the post)
EXTRA CHALLENGES
I decided to try and complete the entire challenge without buying any needs-related reward traits (so for example no 'hardly hungry' or 'seldom sleepy' but things like 'savant' and 'iceproof' were fine) and without using any space outside my 8x8 area except when I was moving things around in build mode. I did end up keeping the Harvestfest gnomes just outside my garden fence so they didn't get in the way all the time, but I sold them all before building the final mansion.
I also decided that once I'd bought a skill-building object it had to stay either in the house (at normal size) or the sim's inventory until I either replaced it with a more expensive version of the same object or the challenge ended. During the challenge I did arrange the objects so that some of the items I was finished with weren't accessible, but in the final build at the end the house had to be liveable and the skill objects all usable. My final $300k mansion was a complete mess and had scaled down paintings and statues all over the place and a roof covered in the gargoyle things from vampires, but I did manage to pack all the stuff into the 8x8 area in such a way that my sim could use everything.
SETTING UP
I called my sim Rapunzel Rapunzel (it seemed fitting for someone trapped alone in a small space, although I didn't make it a tower as I also wanted her to have a garden) and gave her the creative, genius and music lover traits. Creative and genius obviously helped her with her skills, and music lover gave her happy moodlets whenever she played or listened to music. I started her off with the 'Master Vampire' aspiration so that she could have the 'quick learner' trait from having a knowledge aspiration and then clear it out quickly once I started gameplay so I could focus on aspirations that allowed me to gain points quickly (to purchase reward traits such as 'savant', 'morning sim' and 'night owl' that helped with skill gains).
She moved in to one of the lots in Brindleton Bay which I gave the traits great acoustics (for all those musical skills), home studio and fast internet. I think if I did the challenge again I'd pick the 'Homey' trait instead of either 'home studio' or 'fast internet' as although I maxed cooking naturally during the challenge I did need to work on gourmet cooking and baking at the end. With 'homey' I might have ended up maxing all 3 cooking skills before I'd done everything else, but then I could have saved time by cooking group servings of meals instead of the single servings I used most of the time.
I divided my 8x8 lot into a 5x8 room (with a wall three tiles in that extended 3 tiles down, providing a 3x3 space that became a galley kitchen and bathroom) with a door in the bottom right corner leading to a 3x8 garden. Since I have seasons I covered half of the garden with a glass roof and left the other half open to the elements and moved my plants around so that those that weren't in season were sheltered and the others registered as outside (because they seem to grow more harvestables and evolve faster when they are outside during the correct season(s)).
GAME PLAY
As I said I started off by trying to get as many reward store points as a I could so I could purchase the skill-boosting reward traits ASAP. Some of this involved switching to aspirations that I couldn't even complete one level of just to get the points. I also made use of Rapunzel's whims to gain points. In these early days I gained social by telling jokes at the microphone, earned money mostly through painting and mixing drinks and then selling them (the 'prose and pop' drink is great for that. It's a level 1 drink and you can only make it when you're inspired, but it has a decent sell back value that increases each time you go up a level. You get to the point where you can make a $100 profit per drink pretty quickly). I also started Rapunzel's garden so she could start getting her gardening skill up ready to be able to talk to plants for social.
After gathering up all the easily gained points I did the painter, botanist, computer whiz, author and musical aspirations. The botanist one took forever and was hindered by the fact that it wouldn't let me plant anything during winter because it was too cold - even when I made a garden planter and placed it inside the heated house. Also the grafting update has made it almost impossible to get the cowplant berry (or indeed dragon fruit) by grafting and I obviously couldn't get it by fishing it or using the rocket (given my rules about not selling skill items or placing them outside my 8x8 area once I'd used them I didn't have room for a rocket, but if you're happy to keep stuff outside your room when you're not using it I think there is room for a rocket) so I ended up buying lots of rare seed packets and opening them until I got a cowplant berry.
At some point during that time I bought 'Get Famous' and also squeezed in the first levels of aspiring actress and world-famous celebrity (mostly gaining my fame via the streaming drone). I also picked up the Celebruserum and Established Name fame perks as soon as they became available - Celebruserum gets potions sent to you which help with skill building (and sometimes also refill your energy, hygiene or fun needs) and Established Name means your sim gets more money for crafted items such as paintings and books. The potions especially were useful to get through the higher levels of some of the skills, especially those that don't help your sim make money (or gain social) within the confines of the room challenge - for example Charisma, Parenting, Veterinarian and the first 9 levels of archaeology.
I also discovered that 'perform musical scene for tips' (unlocked at acting level 5) increases your social need. By this point I'd maxed out gardening and comedy so Rapunzel's social need was boosted by performing musical scenes (raising comedy), bonding with bees (worthwhile as happier bees make better quality honey and you get send them to get gifts for you) and troll teh forums (raising mischief skill). 'Troll teh forums' also counts as a mischievous interaction and you can make sims dislike you by sending them chain letters or spam money requests (neither of which raises social so I decided that interacting' with the listed sims was allowed. My sim 'knew' people because of the welcome wagon, Vlad 'introducing' himself, club invites & Father Winter. Despite ignoring all of those attempts to contact her the people appeared in her relationship panel and were therefore fair game for sending chain letters and spam requests to) so I also managed to complete the first two levels of 'Chief of Mischief'.
I finished off with Fabulously Wealthy, Nerd Brain (second to last as the rocket thing was *technically* doable so I couldn't swap to any aspiration other than Mansion Baron afterwards) and Mansion Baron, but held off on completing the last one until I had maxed all of the available skills. I didn't bother trying to increase the value of my sim's home until I had the funds necessary to build the whole mansion so that I didn't get clobbered by depreciation costs.
SKILLS MAXED
A list of each of the skills Rapunzel maxed and the main items/interactions she used to do so
Acting - mirror & microphone for the early levels, and then 'perform musical scene for tips' to gain social from level 5 onwards
Archaeology - Levels 1-9: books, studying artifacts for historical insights (note: you can examine multiple objects at the same time for quite a large jump in skill. You can't examine your own paintings but you *can* examine the wall hangings crafted using the woodworking table), refining crystals/extracting elements (from crystals and metals received as gifts from the bees or from lightning strikes on my lot). Level 10: authenticating artefacts sent in the mail.
Baking - oven
Charisma - mirror
Comedy - microphone
Cooking - oven
DJ Mixing - DJ booth
Fitness - books, get energised and use the 'exercise' interaction (I didn't want to buy a fitness machine and have it taking up space)
Flower Arranging - Flower arranging table
Gardening - gardening interactions and lots of talking to plants for social
Gourmet cooking - oven
Guitar - guitar
Handiness - repairing objects, woodworking table (crafting guitars turns a nice profit, incidentally)
Logic - chess table, painting mathematical diagrams on the easel (mostly the easel - I only really used the chess table to get the focused moodlet to help achieve the ideal mood for skill building)
Mischief - computer ('troll teh forums' appears under web when playful even if you haven't reached mischief level 2, and it also boosts your social (although rather slowly))
Mixology - bar (lots of 'Prose and Pop' drinks to get money)
Painting - easel
Parenting - books, computer (browse parenting forums)
Piano - keyboard
Pipe organ - organ
Programming - computer
Singing - 'sing in shower' to get inspired, 'sing song' interaction on piano and guitar to build two skills at once
Vampire Lore - vampire books
Veterinarian - medicine crafting station (note: actually crafting stuff doesn't seem to boost the skill but 'do lab work' does)
Video Gaming - computer
Violin - violin
Wellness - yoga mat (also good for getting a focused, inspired or energised moodlet)
Writing - computer (maxed well before I finished the writing aspiration so there's no real need for writing skill boosts as you'll reach level 10 no problem anyway)
ASPIRATION LEVELS COMPLETED
Level 1 only:
Curator
Master Chef
Master Mixologist
Super Parent
Aspiring Actress
World-famous Celebrity
Level 1 - completed but not counting towards points total
Levels 1 & 2
Painter Extraordinaire
Computer Whiz
Nerd Brain
Chief of Mischief
Levels 1-3
Musical Genius
Levels 1-4
Freelance Botanist
Bestselling Author
Fabulously Wealthy
Mansion Baron
@katoregama Thanks for creating this challenge! I had fun playing it and it's good to know about all these useful methods for fulfilling my sims' social needs without having to find other sims for them to interact with.