Your case supports a 240mm or 280mm radiator in the front and you can have it as intake or exhaust. I'd go with one of these in case you decide to overclock your 6600k in the future.
Well, if you mount the fans as intake your gpu will run a little warmer, if you mount the fans as exhaust your cpu will run a little warmer.
If you have it as intake, you'll want all other case fans as exhaust as you suggest which is what I'd do.
If you mount it as exhaust, you'll want all other case fans as intake.
The Kraken x41 has a 140mm radiator, your case supports a 120mm fan at the rear so it would not fit.
You'd need a cooler with 120mm radiator to mount it at the rear.
It supports fans at the top of your case but it doesn't say anything about radiators at the top, I suspect there would be interference with the motherboard.
Yeah even if those temps jumped up 5c they're still good temperatures.