Re: Removing sims from household
@escapedpolarbear Teen and young adult/adult clothing isn't exactly the same, so I'm not surprised the game would assign entirely new outfits for the sims once you aged them up. I think that even when there's a teen and an adult version of the same item, the game rerolls the outfits anyway.
Right now, you have a few options. If you only want to save the look of the sims, you can bring each one into CAS (enable the testingcheatsenabled true cheat, then shift-click on the sim) and save the sim as a template. Then you'll be able to add those sims to other households you create.
Another option is to create an adult placeholder sim, have one of your sims make friends and "invite to move in," then instead of moving that sim in, choose the teens from the move screen and assign them to the placeholder sim's household.
Finally, if you want to use a mod, NRaas Mover allows moves that involve teens as heads of household. So your two teens could move out together without another adult.