I guess the modelling job was a BS excuse for Gamefreak or Nintendo to push in the BW stuff to fly.
Which from beginning to end (well, the end was IMO the only best episode) BW crippled itself with rushed pacing, 2 planned episodes removed and many mishandled characters, especially the star.
About the last Kenny episode, yes. In the Japanese version, Dawn mentioned to Kenny by letter she thought he looked cool. In America version, cool was promoted to handsome (I do not know about the other languages; any added info is appreciated). Which to me is ironic, because the battle between Ash and Kenny wasn't memorable at all. Heck, it wasn't good when you make one side more dominated than the other.
For what episodes to alter? I choose those 2 clip shows that for some reason is part of the Japanese episode list. Hence their numbers are 191, while I believe the rest of the world saw 189 episodes of DP.
With the 2 clip shows changed, we could have seen the following:
-a part 2 of Ash VS Tobias (plus change Torkoal and Swellow in places with Quilava and... well, I would like Charizard, but any others similar to its might will do (except the 5 Pokemon used against Paul). Reveal most of Tobias's full team.
-an extended final episode. Have Dawn and Ash relax and explore other parts of her hometown like perhaps the lake where she first seen the "mysterious Pokemon". You might as well throw in the bit of Team Rocket where they returned to HQ and set-up their next destination.