No, it has to have water turned off and be completely dry. If your going to do all that you may as well fix the problem at the coupling, and it's less expensive to do
Nope use a union and hose clamps instead
Cut the pipe
Did nothing t try but how the science works I do not see any reason why not if below residential temps
I think it would likely work. Especially in the short term to get you out of a pinch until a more detailed complete replacement can come about.
Yes fixed a leaking male female connection has not leaked