The only thing is that he ends up destroying them with the oreo...well, sometimes it was just a trick to get milk and then he uses THAT to destroy them.On the other hand, the Doctor pulls that kind of stunt all the time. If you think about it, he's mostly a trixter character with no special powers other than being really smart. The Daleks could pretty much just shoot him at any time they are in the same room. But then he goes: "Fear me, I'm the Doctor and I can do anything! Don't make me destroy you with this oreo!"
It's not that they act like they can't, they can't go back on their own timelines (or at least, it has some pretty serious paradox-end-of-the-world consequences if/when they do). There's also "fixed-points-in-time" that must happen no matter if the Doctor and Companions are observing them or not. That's really the only two rules, once they visit a place, they're not allowed to hop back a few days or "start over" and they can't change fixed points in time.Off topic, the only real fault I find with the whole Doctor Who series is that the TARDIS can travel back in time, but they act like it can't to create tension. This is especially apparent with Rose Tyler, who only goes with the Doctor because she can spend months traveling through time and space, only to come back to Mickey waiting in the street for her, just as she left him (since from his perspective, only a few seconds would have passed).
However, every time you see Mickey and Rose's mom, they act like she's been gone for months at a time.
Back on topic, the Doctor really is a good example of a character with oomph, but I stick by what I said before.
Depends on what nifty powers you are referring to. The Doctor is able to sniff and taste things to know what they are and there is a lot of different things he is able to do on the basis of having two hearts (like stay alive longer), and if he is regenerating then that grants him a hosts of different regenerate-y things (for instance growing back a hand and accidentally creating a human clone). On the other hand, I think you're probably referring to the powers the Master demonstrated at The End of Time--these were a result of his resurrection going wonky and not typical. If the Doctor was in a situation where his life-force was being used up at an exponential rate, then it is likely that he could manage stuff like that, but it's not typical.Doesn't the doctor have those nifty powers the Master had, he just doesn't use them? Basically he is a pacifist- as some one in one of the episodes said he doesn't need a weapon he has his companions and allies for that.