Thanks for Sharing!
I don't think the address is relevant to show the user all the time, rather it should be something you swipe to open. Also will there be an option to SMS the keys?
I agree. With the addresses hidden, the chat box could be brought up, and enlarged.
it might make sense to put the pic of group participants or whatever underneath the input box. reading and typing out replies would be next to each other instead of split up by an inch.
having to move your eyes as little as possible while in a chat convo seems like good ui design.
just my .02