Blades are interchangeable with any other parts. I always buy a french (full) tang on my blades, and hack them down to the appropriate size for the pistol handle because sometimes, the tang will be just short for some pistol handles to fit their nut on, or too long (poking out of the handle). That's why its safer to buy a blade with a full tang and use the elbow grease to cut it down.
You should never have a problem with interchangeability with blades, guards, pads, sockets, handles. However tips... are completely another ball park
i've had some parts problems, but it shouldn't regularly happen. you may need to find a file or dremmel to fix the problem, but you can almost safely assume you won't have this problem.
The only somewhat consistent problem you may have is if the tang at the shoulder of the blade won't quite fit into the nose of the grip you're using...but that can be solved with a file or a bench grinder.