Wow! Man, in my world you are on the edge. Lots of members here have done some mods that probably answer your questions. Me? I am a "stock" guy but, I bet, you will get a number of responses.
Also: Search the forum for topics you are interested in. It has been in existence for quite some time and there is a lot of archived stuff to look at.
Welcome. Keep us posted. I have always wondered if the TW would run without a battery (or, a totally dead battery).