I'm not sure what you expect the bump to accomplish. You're not listing bugs you're stuck on. Is it just to get attention for your points? The game is done, out, expanded, released a third time as the Developer's cut, I don't think they're going to change it much at this point.
In Flames of Vengeance, there were full sets for ranger, mage, and warrior that should have been better than Ulthring's set, which was geared more for defense.
You are quite right that health regeneration combined with high vitality does make the game pretty easy. I found that you need to adjust the difficulty as you go, so at level 30 or 35 you should be playing on Hard, and level 40+ you should be playing on Nightmare, that keeps things a bit more interesting. The problem with the health regeneration bonus from Strength is that it's actually really well done. Because each individual point in Strength does very little, but in a huge pile they're very effective, I can't think of a good way to reduce the effectiveness. I suppose leave the damage intact, but reduce the regeneration bonus some more.
Honestly, I didn't mind the re-used stuff so much because it's a minor miracle that the expansion even happened at all. The original plan was to have it much bigger and spread outside the city, but they didn't have the time or budget for that.
For higher difficulty, again, turning up the difficulty to Nightmare was a good idea. It took me more than one playthrough to figure it out, so you're right in that there could be better balance so the game gets harder automatically.
The jumping actually did feel fluid to me. I don't normally spend all my time jumping, but in this game I couldn't resist.