My house is due for some plumbing work and I have decided to go with copper pipe for said work. The thing is I am garbage at soft soldering copper. I never do it so I'm awful at judging the temp and I hate dealing with flux. On the other hand I'm a refrigeration mechanic so brazing copper pipe is my bread and butter. I could practically make a good leak free braze joint with my eyes closed. Also, considering most of the plumbing will be copper to copper connections, I could just use silphos filler rod and not have to worry about flux for most of it. I know brazed joints are not standard for water pipe but I already have the tools, the skill set, and I don't see any way it could be worse than soft solder. Sure it's overkill but is there any other reason I shouldn't just braze my water pipes?
I'm not sure about shower valves in particular but I have devinitely brazed directly to regular nylon core plumbing ball valves before by using the rag trick.in that case you just wrap the valve itself with the wet rag.