There are technicalities that have to be addressed.
For me the ONLY downside to having us all living together as a family is strictly related to unresolved insecurities.
In every other aspect its positive.
As I've said previously-we've lived together (Maca, GG and I) for 7 years. My sister (ourdream) has been living here for 9 months, after being "out of the house" for the 7 previous years. But she lived with us prior to that as well.
I personally think that the benefits FAR outweigh the problems. But it is important to continue to communicate and MAKE those special moments together.
For me-hanging out in GG's room IS just as special as when he had an apartment. It's still set up just like "him" which is TOTALLY different than the way Maca and I set up things/decorate. It's still very.... secluded?
In my mind-it will be an awesome experience for you guys. The concerns I might suggest people watch for, I don't see as issues in your relationships.
"Love As Thou Wilt"