just got it, don't buy the duals though. It's a waste. To answer your questions...
1. The rate of fire is about the speed of a handgun, if not slightly more. Much less than the Shipka, though.
2. It has ALOT less freeze than the Shipka. It's currently my favorite spar weapon because of this. It has the slightest amount more freeze than the updated Handgun. If the Handgun's freeze is 0.1, the AP7's freeze is 0.15
Duals help with rate of fire and clip size, but you sacrifice the low freeze rate.