Basic and Advanced Population Options - Population Limit, Story Progression, Aging, Supernaturals

Thanks everyone for responding :)

Due to recent developments in the game and subsequent forum discussions about them, I have thought of two more "sections" to be added. (I won't add them for now, as the forum is still so glitchy and I don't want my original post lost).
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Autonomy
Given the recent changes to autonomy (woohoo, proposals and even elopment!) and the fact that some people are happy about it and others aren't, show clearly that we need a more nuanced set of options than the on/off we have now.
Options

• None - Sims won't do anything without player interference (maybe this one shouldn't be in there, because it makes it a lot easier to, for example, starve Sims).
  
• Low - Sims standing idle will tend to their needs if those drop in the yellow, no autonomous multitasking.
  
• Normal - Sims will autonomously multitask things (e.g. view decoration, engage in conversation) and occupy themselves (either tend to their needs or do something fun, like read a book or play chess or a video game) when standing idle for a while (basically the autonomy type we used to have before the December 2015 patches).
  
• High - Sims will be more likely to occupy themselves with less regular activities, such as non-fun skill building activities or more advanced social interactions like woohoo (when in the right mood).
  
• Full - Sims will autonomously engage in life-changing activities such as proposal, marriage, try for baby or potentially dangerous things that could kill them.
  

For clarification, each setting adds to the things mentioned in the previous one.

Relationships
The issue of relationship decay has been heavily debated ever since the start of Sims 4, there have been several changes in it through patches, but none have been satisfactory, maybe it's time we got to choose for ourselves.
Options
There is never a warning when your Sim is about to lose a friend - Sims 2 and 3 had phone calls/messages to notify you of it. Also, the bars we have are hard to interpret - I'd welcome the return of the point system we had in Sims 1 and 2 where you could easily see a friend needed some attention because the points were under 60. This will also allow the use of the following options to regulate relationship decay (on a 100 relationship points maximum):

• Low - decrease of 2 point for each day of non-interaction.
  
• Normal - decrease of 3 points for each day of non-interaction.
  
• High - decrease of 5 points for each day of non-interaction.
  

Maybe not neccessarily these amounts, but a system like this. There should probably also be an "Extreme" option, for those who like to play hard (like a 10-point decrease per day) - or maybe just a slider that ranges from 2 to 10. It would be nice to have relationships with BFFs, girl/boyfriends and family members decrease a little slower (a difference of 1 point compared to regular friends). The romance bar would work the same but is restricted to romantic actions only (as it is now). The option of no decay isn't added because it would make the "Beloved" trait obsolete - which may actually be a good thing because it has been bugged since the start of the game and still hasn't been fixed. It may well be easier to change the reward trait for the "Friend of the World" aspiration (which is a silly reward because it also means negative relationships don't decay either, and that's weird for "them most popular Sim in town") and allow an option for no relationship decay by sliders or as a buyable reward trait that does work for more than one Sim in each save.
A certain amount of points should be allocated to interactions, just as it worked in Sims 2. I imagine the underlying game mechanic to actually work this way, but for some reason it isn't shown to us.
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They're just some ideas and they may need a little tuning, but essentially it is about having more choice in these gameplay settings than we have now (or simply having gameplay settings we don't have right now). If anyone has any idea on how to improve these ideas, or has any other ideas, please share them!

ETA: I just realised something, maybe the more "extreme" options should be available by cheat (as @MasonGamer sort of suggested) and not as a regular UI option. It should however be fairly easy to use cheats that don't have to be constantly reactivated.