I'm partially done with that -- I've kept a few of the Maxis houses from the base game for now unless I find something that fits, especially in Windenburg because the construction is pretty distinctive. I do keep the game generated Sims if they're single because they can do all the grunt work like food-sellers, bartenders and the like. I've assigned jobs to all of the housed Sims (my families and the ones from the Gallery); I'm only actively playing four households in rotation: Cali West my teen in the city; Gerald Cline, his sister Danielle, and his daughter from alien abduction Vela. (I saved him and Danielle to my Library when he was still pregnant); Tristan and Yvaine Thorne (named for the hero and heroine of the movie Stardust) who are going to be my farming family eventually; and finally my Liam O'Dourke who I created in CAS. I've been spending most of my time with the Clines because since I'd played them a lot they both had a lot of skills. Eventually I plan to retire them after Gerald purchases a bookstore and fills it with his and Danielles writings (he finished the Renaissance Sims aspiration so he's going to write a bunch of skill books, while Danielle's just started on her writing skill). Once Vela ages to young adult, I'll be ready to take them out of rotation and substitute them with her. Gerald will probably stay single but Danielle may eventually marry and leave the rotation on her own.
I also created a few families for the game; a couple of vampires in my library, my alien family the Travelers, a household with a married female couple who have 2 toddlers, 2 children and 2 teens, other than the toddlers the children and teen pairs have opposing traits (like one is a slob and the other is neat, or one's lazy and the other active). I'm not planning to play them actively -- they're basically window dressing. I downloaded some single Sims from the gallery to put in the Not in World population so I'd have them to fill some of the NPC jobs.
