When I had that leaking (which you know about) under the sink, that weekend (as you probably remember) I posted up pics that the connection behind the drawers where the shower is, both H and C were dripping. All it took was me squeezing my body in there and tightening them down. I like your idea of having them do a pressure test so you have faith that it is resolved. Let me know how that goes.
I saw someone post up pics in the past where they did the peel-and-stick backsplash on their coach and it looked good. I think we'll end up doing it at some point, but I look forward to seeing yours.
VERY GOOD POINT about the speakers. I noticed that the first weekend out how I disliked that. They have FL FR RL RR and they wired 2 of them to the speakers inside and 2 of them to the speakers outside. I really wanted 4 speakers inside. Let me know how you do this as this is very high on my list of To Do's if it goes well for you. Thank you!
TH : 2016 Stealth WA2916
TV : 2012 Ford F-250 PSD