Yeah, this is a good point. What happens if you get stranded or something. I haven't figured that out. One solution might be to give you more suggestions of who lives nearby so that you could ask someone else if your ride falls through.
I actually have not solved the schedule problem either. Basically just telling you who passes who and let everyone figure it out. Maybe I'll add a quick schedule prompt or something for folks who work different hours (to filter on or something).
Thanks for the feedback.