WildHobbits

I would go with the 502. It is a great mouse, while I don't use one myself, I have used my friend's and it was great. Also, it is on sale for $60 on Amazon right now.

Think I'll stick with the Castor. The G Pro after looking at it again seems a little too simplistic and it lacks any kind of finger rests. From what I can gather the G seems like it may have a bit better sensor, but since I'm not looking into any kind of competitive gaming I guess that's ok.

G and the Castor are two different shaped mouses, one is ergonomic than the other, if you like a tight fit in your palm go for the castor, if you don't then go for the G

It really depends who you are. I would say most, including myself, would go for dual 1080s. However some people stand very strongly with single card configurations just because they typically have higher minimum frame rates and less stuttering in game, however SLI has gotten much better over the years and while you still may experience some lower minimum frame rates, stuttering shouldn't be too much of an issue. You would definitely get more performance with the 1080s, it is really just if you care that much about minimum frame rates and the fairly low risk of stuttering.

The wire leading to the right driver is shorting out or breaking. Your options are to pull the headphone apart and hope you can both fix the issue and get the headphone back in one piece, or buy new ones.