Okay, here's my opinion:
maybe.
A. First, you have a problem. Bullets use the simulation ShotBullet. After two seconds, the simulation terminates, and with it the bullet -- regardless of whether it hits anything. You _could_ use ShotShell, in which case the simulation lasts 20 seconds, but ShotShell actually draws the shell, which means an even greater poly load.
B. Second, I doubt the juice drain is coming from the camcreates. More likely, it's coming from the collision detection, graphics engine (maybe) and sound effects.
C. Don't use CreateVehicle for shrapnel. In multiplayer, you don't have the bandwidth to do this (you don't have the bandwidth to setpos either).
D. When shrapnel was brought up a while ago, I muttered something about claymores. Now you can get the CoC_Mines addon, and see how Jostapo and I solved many of these problems. The .pbo will unpack with pbotool, we've doc'd and commented the scripts, and you can use it as long as you give us credit for the code you use and use it only for OFP and only for non-commercial purposes.
E. From our experience, 200 pieces of shrapnel is about the limit