Hello, I'm new to Pioneer and games in general. I have several questions:
1. Are there any extremely in-depth fighting, flight, landing, and equipment tutorials?
2. Are there any mod tutorials consisting of, but not limited to, an easy-to-understand (<- Optionally) API reference (Ex: Make a ship (model), auto-fighting, etc.)
3. Are there any other things I should know? Like, what does the ECM do?
You could look at the wiki: http://pioneerwiki.com/wiki/Pioneer_Wiki
There are some basic tutorials and informations.
You could also search for some videos on youtube. There's a "Let's play" series from bchimself and some videos from Brian Ronald that I found useful to figure out how to deal with the in game physics.
ECM is useful to interfere with missiles.
You liked my videos? Cool!
EquitemTotum: Unfortunately for the dissemination of information, Pioneer changes very quickly indeed. Pretty much everything you listed in your question has either changed recently, or is likely to change soon.
Rob maintains an API reference here: http://eatenbyagrue.org/f/pioneer/codedoc/