I don't see how it can replace a face to face conversation... I've been living with housemates for a long time, people come and go. We always try to find ones we have a good bond with, usually people who are already in our community. I'm actually the least active member there so people know other people better than they know me.
Personally, I would find it very difficult without personally meeting a person. Especially if it is a guy... We are currently 4 guys and 2 girls in our household and we have a spare room so if we were to find another housemate it would be a guy, and I as a girl would like to know the person and feel if I can trust him and feel free around him. I mean, I want to be sure I can walk around the house with minimal clothes and we both will feel alright with it, even if we feel attracted to each other. Ones we interview a guy that was too happy there are girls in the household, like he never seen a girl before.... for me it is creepy, even if he is a good guy.
I really hope your app will work, but I don't feel it is right for me. An app can't show vibes... it is even more important for me than having a non-smoker vegan housemate (most of the housemates are meat eaters and I'm fine with that) I can even accept a smoker, as long as he smokes outside, but not a creep.
BTW, I'm 33... always forget I'm over 30....