1- Test it with stock fans, if you don't get good airflow add more fans.
2- The stock cooler of SB is very good, and SB overclock pretty well on air. Test it with stock cooler, let me know your temps. If you get high temps, go with a better cooler.
3- Not a problem, but I suggest you go with something more better. Titan Fenrir, Megahalems Rev.B, Silver Arro, NH-D14, Archon. If you really want get the max of that CPU you will need one of those coolers.