I'll give this a shot.

The character I have in mind is gonna be an ex-raider struggling with drug withdrawal and anger issues. The guy the team needs working on the sidelines to make and repair things. But when he fights, he's gonna fight. And he's also going to be really hard to get along with, and he could also end up causing lots of trouble if he's provoked. Which could very well be a lot with his temper. Expect lots of tension created between the player characters with this guy.

If we take the Green Line, New Reno is the first stop from New Vegas. Between the two points are Tonopah and Hawthorne. New Reno to Portland is where we'll be leaving the more settled Core Region, and everything from Portland onwards to Pittsburgh (The Pitt) is free game. Though we could possibly come across some throwbacks to Fallout Tactics in Chicago as well.

The Blue Line takes us to Van Buren territory in Salt Lake City and Denver, and how much you want to pick out of Van Buren is up to you. After Denver, Lincoln to Kansas City could also take some stuff from Tactics if you so wanted. From there, we'll see what awaits us before we reach DC.

Aside from possible Legion stuff in Arizona and New Mexico, the Red Line would allow us the most creative freedom, knowing how Texas and the South haven't really been covered all that much in the Fallout series. One suggestion though, Phoenix would probably be important enough to be a stop between New Vegas and Albuquerque, would it not?