Sounds like you have a logical plan. At least for the short term. Longer term things will evolve as they will.
For those open enough to get their head around it - the BF/GF etc is fine. For the conservative - best friends gets it covered.
In the current economy and for a variety of other reasons - cohousing makes a lot of financial sense for increasing numbers of people. As does it in balancing time/responsibility challenges.
Just proceed like it's the perfectly normal, rational thing to do - which it is !