I concur, and actually it seems Fallout 3 already did this to some extent --- the Craterside Supply Shop, for one, seemed to always be closed and I would have to loiter outside for them to open up, and there were Brahmin trade routes that had actual routes and timings and such. I would be frankly surprised if Fallout-4 had static, never-moving NPCs.
As for vehicles... on the one hand, it CAN get tiresome to get from Point A to Point B far away on foot... but I have to err on the side of immersion, here. If you could find/repair a motorcycle, you'd constantly be scrounging for fuel (if it were in any way realistic) and the condition of the roads would make me nervous about driving at anything faster than a walking speed, anyway.
That said, it MIGHT be a neat idea to have a Highwayman kind of vehicle to represent your Fast Travel... as an added complication, you would have to return to your "mobile base of operations" at the last Fast Travel point you left it, in order to Fast Travel to another point. Of course that could get tedious if you traveled by foot some distance and THEN wanted to Fast Travel again. My thinking was that you could use the Highwayman as a sort of portable STORAGE solution. Ulterior motive revealed. 
For over-land travel, though, I would be more comfortable without vehicles. It's one of those situations where what you WANT is not what you REALLY want. Some restrictions are actually good, and I think being "forced" to walk everywhere would be "good" for us. The reptile brain, however, relishes the idea of my dog wagging his tongue as his head sticks out the window and then I dift into a stop in front of some raides and plant one boot solidly outside my car door, then another, then rise to stand with twin magnums in hand, slowly raising my head to reveal a manic grin. ;D