Not sure how much time you have to devote to music, but something to keep in mind: this one project doesn't have to be your only outlet. Doesn't sound like the other guys are hounding you to make it your main priority, and it wouldn't be the end of the world if you had something else take off and leave them in the dust, so play with them when y'all can get together, but keep looking, networking, auditioning, and writing your own stuff.
I've found that, even though I'm not a great singer or multi-instrumentalist, writing and demoing my own tunes gives me a lot more say when I do find cool people to play with. Rather than being stuck with whatever the bossy guitarist/songwriter wants to do, I can say "I've got some tunes, check it out" and guide the band towards stuff I want to do too.