I don’t typeset music myself but I’ve heard that LilyPond is very good. It is based on LaTeX.

I use Liberapay and have been pretty happy with it. Have found quite a few of the people and projects to which I would like to donate, but not all.

This seems quite reasonable to me, and if you are doing the more risky activities, then presumably you’d get some insurance to take the edge off the rescue charges.