1. BST is they Buy,Sell, Trade section of BYC. 
2. I can't speak for all that list on Craigslist only myself.  I welcome folks to come see the birds.  They are not allowed to touch them and we require folks to spray the bottom of their shoes with Oxine before coming back to see the birds.  If they are newbies at hatching I will try to direct them to the cheaper eggs we sell and then give them one or two extra eggs from a pen they seem to like.  
3.  I don't buy hatchery birds.  If you just want backyard birds for a hobby hatchery birds are just fine. For us put boys want to show birds so we went with eggs an chicks from reputable breeders in our area.  
I would say ask lots of questions and if something doesn't seem to mesh with what you have researched then find someone else to buy eggs/chicks from.