Loud noise in the pipes when I turn off my hot water
Easy fix, if it is water hammer, is to install a water hammer stub -- just a capped pipe on a T downstream of your boiler.  If that doesn't fix it no harm done.

You should also ensure that you have an expansion tank in the system.  You'll need to check your boiler manual to determine if it has a backflow check valve, in which case the expansion tank also needs to be downstream.