I didn't watch so much of the earlier (ie, pre-2000's) series, so can someone tell me, in these earlier series...

1) Did the Doctor ever try to save a race before doing any damage to it? If so, then I don't see the problem with him carrying on that 'moralist' kind of thing.
2) Did the Daleks (or any 'famous' race) ever come back after being 'gone forever'? If so, I don't see the problem with them doing that again, either.

I think that RTD did something that he was wanting to do, which was for him as much as for the audience. He wanted to get every main character from his time together to end his Doctor Who series, sort of a finale in more ways than just the fact that this particular season is ending. I think it was sort of like a reunion before everyone goes their seperate ways, and I don't think RTD is the kind of guy to want to leave it on a "to be continued" way, but more the kind of guy to leave a clean slate for the next writer. He wrote out every single person but the Doctor, allowing Moffat to set up the Doc's mood, companion, whatever. It's all up to Moffat now, as it should be. If they kept any of the existing companions actively involved, it would have been a bit eh for me if I was a writer.