Looking forward to seeing your progress, especially interested in your shower plans. I'm at the same point myself, will need to frame in the bathroom/shower area soon, but not quite sure how to ensure against leaks. Your trailer looks a lot like ours, only a little shorter. Trying to figure out a way to best use that odd space in the V-nose is proving to be a challenge.
For a low-tech solution to nature calls, we got this:
http://beprepared.com/product.asp_Q_pn_ ... at+%26+LidIt's light and portable, and on sale right now. :-)
We paired it with an outdoor privy/shower tent for our trip this summer, but ended up so close to the restrooms at the campground that we never needed to use it.
Robin