1. Unfortunately, no. Terminals 4-6 are connected via LONG underground tunnels that you can walk, or wait for the golf cart driver. T 6-8 have walkways along the inner corridor of the terminal. Going the length of all of them is not short. I only went from 8 to 5 and didn't venture over to T4 (and this was years ago). There is no walkway to TBIT except pre-security. I heard that American has a shuttle from T-4, gate 44 that goes to TBIT and their American Eagle remote terminal but I haven't tried it. It was supposed to stop at T-6 for USAir as well. Can't say that is still accurate anymore.
2. I don't know but any searches I do don't say that it has Pre.