I played the crap out of Gothic, Gothic II and Risen (the latter just recently for the first time thanks to Humble Bundle) and now I'm round about seven hours in in Risen 2.
While I agree with you about the lack of some core mechanics from it's predecessor I don't think the game is bad or even "worthless".
The world is still magic and beautiful due it's handcrafted landscape and I still love the rude talk of the ppl
Finally they gave the graphics engine an overhaul, R2 looks just awesome (especially compared to R1 which just looked like a small improvement against G3). The characters and their animations are such a huge step-up from R1.
As I said I agree with you in terms of some features which are missing from the predecessor, like magic or the possibility to loot ppl before helping them getting up.
At this point I can't give a more detailed verdict, but I like the freshness and changes of R2 so far because with R1 (despite all of its greatness) I got a little tired of the basically same mechanics and gameplay since G1.
Piranha Bytes is now on Facebook and there they already confirmed that they're working on a new title, but yet can tell the fans what it will be.