To answer some questions that have come up...
Regarding Life Plants, I'm going to rule that they are not allowed under the same logic of no ambrosia. Anything that alters your sim's lifespan is a no-go for the challenge. The reason being is that you're racing against the clock (all be it a very long and slow clock) and being able to reset it could make for an excessive amount of points. After all, it is easy to have every single sim in the family get 100K, heck even 200K lifetime points if they have forever to live.
Regarding the lifetime points, it counts for total points gained over the course of the sim's life. You're free to spend them however you like, they still count. If you mouse over the treasure chest on the rewards tab it'll give you your lifetime points earned amount.
Regarding different aging settings, the challenge is balanced to be on 'normal'. Epic would give you more time to earn points before sims died, thus giving the epic players an advantage over normal length. That being said, you're free to play a different lifespan speed Legacy Challenge, you'll just have to compare your scores to others who have chosen the same lifespan setting, rather than normal.
Regarding harvesting fruit from community gardens, that is not stealing. You are free to sell/eat/plant the fruit.
Regarding portraits, they must be painted portraits. Cell Phone pictures do not count.
Regarding children and lifetime wants, you may assign lifetime wants when they crop up. You may also purchase the "change lifetime want" perk and select any want available for any sim, as many times as you wish. Keep in mind that once a sim has fulfilled their lifetime wish, you cannot change it to fulfill it another. This is how it is supposed to be. If you are after all 32 points, you're going to need 32 different sims to fulfill their lifetime wishes.
You may also select the "Midlife crisis" perk to re-do your traits, but if you do that, you must randomize all of them (unless you are using family trait)
Regarding the question about books earned from opportunities. Those books are fair game to be sold for cash, even if your sim is in the criminal career track.
Regarding player created sims. While you are not allowed to move in/marry sims of your own creation, you ARE allowed to move in/marry their game-generated offspring if they happen to reproduce. Bear in mind that they must not be 'rich' to be eligible.
Regarding the question about collections. In an early beta version of the rules, i had some lines about getting points for complete collections, but in testing I found that either the collection was a lifetime want, or it was made stupidly easy by using the collection helper. Rather than banning the collection helper, I simply left off the collections from the point system.
Regarding the question about rebuilding the Legacy House. As long as you don't move your Legacy Family to another lot, there is no rule against tearing down your Legacy House and rebuilding it from the ground up.