I let MCCC control the moving stuff, for the most part. I stopped having single sims move out, because it was splitting up premade families. So instead of the Caliente/Lothario household having one house, they ended up with occupying 4. I leave the premades alone, unless I play them.
I have done makeovers on all premades, except DU, and saved them to my Gallery. They will be put in an empty save, in houses I will build or download for them. The rest of the world I'll populate from my library, or the Gallery. I will tweak MCCC (again) so that it will not only spawn YA/A sims, but also families (it used to spawn families with children and toddlers, don't know what setting I messed up).
NPCC will take care of the generated townies, so there won't be too many of them. I've used this mod a week or so now, and I really like it. There is no over-production of sims anymore, and the control it offers is awesome.