In a CZ 75 variant, the FPB directly influences the SA reset distance. Removing the FPB essentially turns an SP-01 into an SP-01 Shadow or Pre B CZ 75. CZ Shadows, Tac Sport and other non FPB CZs can have the shortest SA reset distance possible within the platform. When removing the FPB, the FPB Lifter Arm must be replaced with a Sear Spacer. If it is left in place it is possible for it to get jammed up in the hole in the slide from the removal of the FPB Plunger. Installing a wider Pre B/Shadow Sear is another option if you wish to avoid using a Sear Spacer.
The Firing Pin Block is a drop safety mechanism, much like it is in a Glock and many other pistols. The way that i see it, non FPB models are for range or competition use only. I suggest leaving the FPB intact to start, you can choose to remove it later if you feel the need. The value of the potential gains are debatable, we are only talking about approximately 2mm.
Asking questions is a good way to learn, we all had to start at the beginning.