Yes, many trusted sources have confirmed that Sony's planning on the new king and some also believe that Z7 is kind of a test of the market for deciding whether a new king should be introduced or not.
For gaming, I don't play games so I cannot answer your question.
For the Kimber Cables, JUST go get it, period. I listened to my Z7 with balanced Kimber Cable (cable belongs to my friend) connected to LUXMAN P-700u (belongs to my father) two weeks ago when I back home and ordered my own Kimber Cable unbalanced version the day after. It really really made things different, I was totally shocked, and after that I understood the reason why some reviews say Z7 is a competitor of HD700. TBH, before listening to this combo, I thought this statement was a joke but this Kimber Cable does blow me away. In short, this combo ,made Z7 sounds more flatter and overall well controlled, it feels more like a flagship just under the king.
Anyway, if you are in North America, go to Sony's official website and search Z7, they just have these cables in stock and ready to ship today.