I have a4 port shower valve body I am connecting CPVC (1/2") pipes to.

The shower valve is solid brass with all four ports being 1/2" F.I.P. It
also comes with four 1/2" brass nipples. So I can get four 1/2" CPVC M.I.P.
transition unions (slip CPVC x brass) and screw them directly into the
valve body. Or I can screw the 1/2" brass nipples into the four ports on
the valve body, and get four 1/2" CPVC F.I.P. transition unions and screw
them onto the other end of the nipples. Is there any advantage of doing it
one way versus the other?

I have another question regarding an outdoor shower. The pipes are being
routed on the inside "side" of the 8" exterior concrete wall. The pipe runs
up to about 72" above ground, then I drilled a hole through the 8" wall. I
know on the other end I need to secure a shower arm that is 1/2" male, but
how do I make the transition from CPVC pipe to the shower arm? If it's an
interior wall I would have studs there and will put in a brass drop ear 90
set a little back from the finished wall. But this is exterior wall, so I
think perhaps I put in a CPVC elbow then continue with the CPVC pipe through
the wall and around 3 inches from the finished exterior surface, change to a
transition union (slip CPVC x brass) F.I.P. with the brass end flush with
the finished wall? Is this the best way to do it? When I screw in the
shower arm, will it end up breaking or twisting the CPVC pipe if I turn it
too hard? Or do I need a drop ear 90 that mounts on the inside?

Thanks,

MC