I-Home improvement

[swampboots]

OK here is what I am trying to do and part of it is to make this job easy. I never have to "deeply" worry about that PVC part leaking, as that can always be addressed (leak would be minor compared to current size of leak) as I now have a quart of water per day leaking from this rented apt's bathroom below into a handy bucket in the basement.
Previously I had a leak for years ( dripping into basement) as I had stupidly built a shelf above the tub sprout indented in the wall and had to re-grout for eons until I replaced the tile with a single piece of marble. I have been dealing with all forms of leaks from that area for so long it reminds me of the line from Jack Nicholson "you do not want to hear the truth".
So of course you slide rule dudes can pronounce fixing this problem in the classic no shortcut, do it right once, and "forgetaboutit" method, but more to this little PVC part......
Ok, real problem now seems to be a leak somewhere in the pipe above the shower body mixing valve to the shower head (in that 4 foot span in the wall). Do not know where the leak is exactly, likely at the sweat joints in the wall in that pipe length. I could poke a hole in the wall with the camera arm connected to a computer, but can't find it in my basement yet,lol.
I want to skip the current shower head ( and not annoy nervous tenants with a gut renovation of the tile area) by installing instead this mixing valve diverter spout:
https://www.google.com/search?q=tub+spout+mixing+valve+attachment&tbm=isch&source=iu&ictx=1&fir=VE1Ypfns4TYVMM%253A%252CeQ5MLYgmWVrlXM%252C_&usg=AFrqEzfYYEcWnD_c_5n5EuUhOrlT7jFuGA&sa=X&ved=2ahUKEwjSh8D9ufncAhVCT98KHV44ANIQ9QEwGHoECAQQBg#imgrc=VE1Ypfns4TYVMM
and then installing this as the new source of water for a shower:
https://www.homedepot.com/p/Delta-1-Spray-Handshower-with-Slide-Bar-in-Champagne-Bronze-Featuring-H2Okinetic-51205-CZ/203990684?cm_mmc=SEM%7CG%7CVF%7CD29B%7C26-3_FAUCETS%7CDelta%7CNA%7CModel_Numbers%7CInventory%7c71700000033435189%7c58700003893459131%7c43700031221837296&gclid=Cj0KCQjw5NnbBRDaARIsAJP-YR9vZIk6yLddZSD0aSQv-Z0aFhjarKsEjoynX_zusUTazFxIwm-5rrYaAgqsEALw_wcB&gclsrc=aw.ds&dclid=CMea9a_l9NwCFQNBDAodgX8PWQ
One thing I have not figured out is if once this new tub spout is installed and hand message shower head is activated , does all the water go to that new shower head? Are there no leaks from tub spout (usual) other opening, or is there residual water in the copper pipe in the wall connection from the shower body to the old shower head going to continue leaking in the wall?
Well I will soon find out......but wish to have every conceivable part for this project ready in seconds!!!!