That is a lot of questions that cover a lot of musical ground.

But... I have a question for you. Are you just getting started?

A lot of the questions you ask seem to indicate that you don't really know very much about the music business due to the nature and topics you're asking about.

So to answer most of your questions.... As a beginner , none of those things are things you need to worry about at this point. Just work on the music. If it's writing, performing, or both, just work on that.

In the meantime, do your research and study. That book Mike recommended is a great starting point.

Hope this helps you find your path

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.