You can buy replacement window seals from places like Outofdoorsmart.com, Inland RV, and possibly Vintage Trailer Supply. I've tried using the stuff you can buy at the local big-box home improvement store, but it just isn't as robust.
Think seriously about your flooring, especially the thickness. I assume you are piecing it in around your existing furnishings, so beware of what doors it will interfere with, etc.. Since there will be dramatic swings in temperature and humidity, you will want your flooring to be able to move, and you will want to leave adequate gap around the edges for expansion.
For your power questions, I would suggest that the only way for you to know for sure what wires go where is to get out your continuity meter and try to map it out. Chances are that a previous owner has changed some things up, added a battery, then removed it, etc..