I usually collect them, then they become available from the bed (I do use ccmod though, mgiht not be vanilla ihdno).
As far as buying stuff from the store, I'm pretty sure you can unlock edicts that allow you to buy sextoys.
You can't. You can skip doing them every day for a few days without degrading them. The entire point of the game is to build up a roleplaying experience. There is no 'content' at the end of the minigames. If the mini-games are not enjoyable, you're not forced to play them to win the game, or at least, you only have to do it a few times for specific playthroughs. Not really sure what else there is to do in this game but mini-games, but that might just be me.