Have the same ones. Old charger style is annoying. Battery doesn't last as long anymore.

Depends on the flooring used. A floating floor would be best. If it is not spongy feeling, it'll probably last a long time. The mold will get worse over time. Do not use a sealant on the wood. It'll trap the water. If you don't fix the cause of the water, it will begin to smell musty.

As a contractor, I'm sorry to say that there is little you can do to fix this properly without disturbing the tub and tile. You can try to carefully pull off the bottom row of tile and you have a chance, but if one breaks, it's really hard to replace it. Demolition is your only real option to fix it properly.