To answer your first question, I believe the AMO speed rating for that particular version of the Havoc to be between 225 to 230 fps. Now that speed is gained without having any items on the bowstring besides a single brass nockset. If you have a string loop, rubber eliminator button, peep sight or string silencers installed then you can expect a lower speed out of the bow.

As for your ability to shoot Shockwaves with your setup....assuming you can get 220 fps out of the bow with your 541 grain arrows...you would be generating roughly 58 ft. lbs of KE. That should be sufficient for a properly tuned bow with the Shockwave expandables in my opinion. But that opinion is based on alot of assumptions. Your best bet is to get the bow shot through a chronograph and then go from there.