The PP20 suffers with all these same issues. Assuming that it's similar in design to the pp20 - I would also get some thread lock on the hammer adjust screw on the back, as mine had a habit of slowly walking its way out over a few hundred shots. (Count the number of turns out so you can put it back in the same without adjusting power

)
I wonder if you too can swap the air cylinder for the PP700SA one. I've added that to my PP20, and I go through a lot fewer o-rings!
Maybe I'll save some money and just see if I can retrofit the sights from a pp30 to my pp20