For that to be done safely, I would call a contractor.
Answer 2there is no way to do this without cutting hole behind tub, if no hole could be cut then you would have to come in from the front. I would not do this if i had to come in from front unless you where ready to retile.
Answer 3In the past, I have seen ads in home improvement magazines which showed a hose type shower extention which used a rubber coupling which slipped over the bathtub spiggot, and which then clipped into a bracket which mounted to the wall ABOVE the tile line. I also saw ads for a similar device, except that it was a REPLACEMENT spiggot with the hose permanently attached to its side. With this one, you would remove the old spiggot by simply unscrewing it and installing the new one without having to damage any tile or wall. It has been a long time since I last read a home improvement mag, so I don't know if the products I've described are still available.j3h.
There is a website that sells shower valves which cover your old Plumbing and keep you from having to tear out a bunch of tile. Some minimal tile removal may be necessary but the shower fixtures will cover it. You can find them at www.versi-shower.com.
No, you must expose the leak and usually the only way is taking off the wall covering. Not a huge job.
Replacing an old or unwanted shower head is usually as easy as unscrewing the current head and replacing it with your new shower head. Simply screw the new shower head on and tighten it with pliers.
Yes, because walk in showers are much easier to maintain and clean than traditional shower stalls. A walk in shower stall will also have a height adjustable nozzle.
You can't shower without getting wet, unless you are taking an imaginary shower. The whole point of a shower is to get clean, which you can't do without water.
A leaking shower valve by installing a new cartridge.
Usually you cut a hole on the other side of the wall behind the shower. Very often this is in a closet. If not, you can use the piece of sheetrock to make a door or put it back in place and retape the joints.
If they leak, they need replacing. No, if they leak they don't need replacing. If they have been scored or eaten they need replacing. If they only leak they need to be re-packed.
Yes.
Wear a shower cap.
Yes
Open up the actual shower head and remove the factory fitted restrictor.
Yes, shower radios really work without getting wet.