Can only answer to your first question. I've found the recoil on my P99 QA to be managable once you get used to the gun, which I am still in the process of. What I've found is it's difficult to adjust the sights on the gun to aim where you want. This is probably due to my inexperience more than anything else, but I had them dead on one day at the range and decided to play with them more to see if I could get them right again, and it's never shot as accurate since and I try and find that sweet spot every time I go to the range.
Over the P99's a fantastic gun. BTW, in regards to your arthritis, you can adjust the grips so maybe to lessen the pressure of the recoil on a particular part of your hand. Just a thought.