Here is a nice review on the H70: http://www.overclockersclub.com/reviews/corsair_h70/
Answer #1 - The H70 is supposed to fit all Intel as well as AMD sockets. Verify this from Asus as well as from Corsair.
Answer #2 - One fan must be in the CPU fan header (or else the motherboard may not POST) - I would plug in the 2nd. fan into a separate fan header. This will give you better control. Another option is to directly connect the 2nd. fan to a Molex connector powered by the PSU (no speed control - full speed all the time).