dont know how much good a supressor would do tbh, depends if it still allowed some air into the supresor can, as the venting in barrels allows the air to have less spin effect on the paintballs when they leave, as ive 1 barrel for my a5 thats unvented and its horrible accuracy wise, my demon (spool valve) on the hand is stupidly quiet compared to the a5, as its for your phenom have you considered trying a barrel vented more like a deadlywind or a full bore unitec barrel as there vented most of the way along unlike say the standard tippy barrels.
as for the bolt i personally wouldnt know
hope thats some help