I've been thinking about deleting my rear wiper, for one my Reimo 3000 bed almost completely obscures any view out of the rear window, and secondly I've never used the rear wiper on any vehicle that I've owned because I don't think it's a good idea to be scraping all that road grit across the glass.
Looking at your pic' it looks so much cleaner (no pun intended) without it, care to share what you did about the rear washer tube? can you disable the motor by simply pulling a fuse?