FPS doesnt necessarily mean performance issues. I have around 110 FPS while alone and still get like 60-70 in a raid setting. Some things will bring my machine to a crawl. Other things will make me hitch/stutter or lag spike. Other things give graphical issues. Other things have UI problems/load screen problems/long load times/screwed up things when you shut the game down/memmory leaks/ability lag or no fire or registered fire with nothing happening or ability no fire with a cooldown anyways.... all those things have nothing to do with FPS and everything to do with performance.
FPS is a good performance indicator, as if something brings your machine to crawl you obviously don't have a 100FPS there. A lot of which probably boils down to hardware and/or driver issues however. As personally I have no slowdowns. So either it's a hardware problem per se, or the game is conflicting with certain drivers or vice versa.
Also in terms of loading screen issues, I have none with the average loading screen taking roughly 5 seconds. SSD's work like a charm. Sure on traditional HDD it may take time, however, that's primarily a hardware issue moreso than a general performance issue.
As for the last part of your text "ability lag or no fire or registered fire with nothing happening or ability no fire with a cooldown anyways"... I couldn't descramble.