I think you are extremely bottlenecked by your CPU btw. Your GPU should score alot higher.
I think your mobo can handle a 9900k? They are decently priced now, plugNplay and you got 8/16 cores instead of 4/8.
This only happends if you cheat, and go mental with duping. But the cheaters can go mental now cause they upped the limit.
Anyway, I had no problems at all, completed it. I was not a fan of any of the endings.
I dont really have any bugs. Sound is plopping in some area's. And I think optimization isnt fine tuned yet.
I think most complaints come from the older consoles with terrible 5400rpm HD's that just cant keep up with loading textures and whatnot.