They did do things with the criticisms of the last game, just not your criticisms of the last game. For everyone who disliked combat in oblivion, someone else liked it. They made some small changes, to try to win over those who disliked it, but they were smart enough to stick with what worked enough to not piss off those who enjoyed it. now, I haven't played the game, so I can't definitively argue against your other points, but from everything I saw in the gameplay trailers, they improved on the non-player character aesthetics, they improved on the conversation, they improved on everything.
The thing that you seem to not understand, is that you don't have to completely redo something, in order to improve on it. Oblivion was a huge success, why would they radically change everything into a completely new system that would be received unpredictably by fans. They made minor changes to everything, trying to make a very very good system, just a little bit better. and from everything I have seen, they appeared to be successful. Skyrim did exactly what a successful sequel should do, they didn't just copy-paste the game like CoD, but neither did they just release a completely different game with superficial similarities and call it a sequel like Dino Crisis 3 did. they chose the correct, middle-ground option. To retain the same feel of aesthetics and gameplay, while trying to make everything a little bit better, but not changing it so much as to lose all the things that made oblivion successful.
The thing that you seem to not understand, is that you don't have to completely redo something, in order to improve on it. Oblivion was a huge success, why would they radically change everything into a completely new system that would be received unpredictably by fans. They made minor changes to everything, trying to make a very very good system, just a little bit better. and from everything I have seen, they appeared to be successful. Skyrim did exactly what a successful sequel should do, they didn't just copy-paste the game like CoD, but neither did they just release a completely different game with superficial similarities and call it a sequel like Dino Crisis 3 did. they chose the correct, middle-ground option. To retain the same feel of aesthetics and gameplay, while trying to make everything a little bit better, but not changing it so much as to lose all the things that made oblivion successful.