I don't know what passes for what in GA ..but you can get on very slippery slope as to enforceability
of a contract over something that is improper by local or state law. .
But a LT written lease stands as written especially if it looks like, smells like, and parties perform just like it says...and pay as required etc THere are other ways to do it , none perfect , ....but I agree its smarter to discuss things with counsel ahead of time .
I don't keep a statistical count ..but my guess is a good percent of live together deals break apart.