Re: Managing as a roommate
@Sanrokero Hi! Sorry, the game does not allow us to play sims as roommates. If you want to play that sim again, you would need to move them into a lot, another apartment or a house. Finding them in the game depends on where they are stored. Go to Manage Worlds and then, from from the Map View, click Manage Households.
You have two tabs to choose from; My Households and Other Households. My Households consists of those you have created or played or favorited in the game (they have a heart icon button). Based on what you've described I'm guessing your "roommate" sim will be in this tab.
If your "roommate" sim is not found in that tab, then click on the Other Households tab and filter by Not In World using the options in this image. Roommates are not part of any household and therefore are categorized as Not In World. Also, your view may be slightly different if you have Neighborhood Stories disabled.
Once you find your "roommate" sim, click on their thumbnail and click the Moving Truck icon to move them into a lot.