Your latter problem is exactly what I have been experiencing for the last few months, though actually much worse. My fuel pump has been slowly dying for the last few months and recently got too bad to drive even around town. If i were to take a guess i would say more than likely it is a fuel pressure issue, and quite possibly is the fuel pump. I'd suggest you get your hands on a fuel pressure gauge (if you don't already have one, I got mine at harbor freight for 12 bux) and first check the pressure after the pump, make sure that is sufficient. If that's ok, check it at the fuel rail, if its down there it could be the regulator, also check under load, mine didn't show much of a loss at either ends, but once it was driving, it dropped significantly above idle.