No disrespect intended, but nobody can do EVERYTHING. You need an electrician or mobile RV tech before you take another step or make anymore decisions. A person who is familiar with RV wiring would be the best for you.
Not sure what you mean by bypassing the converter and go direct to battery with shore power.....but at face value that can't be done. Something needs to keep your battery charged, and that's the converter when plugged into shore power. Sooooooooo......really...hire someone, tell them what you want the end result you're looking for as far as use is concerned and let a pro do the work.
No use in trying to explain the technical stuff, just hire it out...you'll be happy and SAFE in the end.
With all due respect, Mike
(There is no 220 volt ANYTHING in your trailer, none, nada. People get mixed up because of the plug configuration...it looks like a 220 plug but it isn't.)