Awesome to see some more interest! 
To answer your questions, The location is flexible and if you'd like somewhere specific to aid your backstory, then I'd be happy to oblige. However, for my purposes I'd say it is somewhere in the vicinity of St. Lewis (North or East, most likely.) 
Characters familiarity with each other is completely at the disgression of the players. I have set up the story so that even if they have no familiarity they will still end up meeting each other, so there is no pressure to create that situation on your own if you don't want to.