As a dedicated fest reader (and extremely occasional writer), I have to admit that th AU/AR split might cause some major problems in judging/rating. I found that your explanation rather muddied the clear definitions (I thought :^) I'd previously held. I believe that many of your contestants might have the same problem, or at least come up against the issue that many people have their own ideas of what the terms mean, and the ratings will reflect that, rather than the contest's descriptions. I was a real fan of the Romance/Angst categories--they were incredible, while the wartime/post-war entries were often quite thought provoking.
As for the art/fic collabs., that again might be just adding a world of headache to the mods. I guess I'm picturing late submissions, submissions that change during the process of being written/drawn, and I know for a fact that the muse is often hard enough to entice in just one medium let alone two! That said, it is an intriguing idea, and the art/fic collaborations I've just begun to notice in the past few weeks have been breathtaking!
I think the min/max lengths may be a great idea, or at least pair two competing submissions in the same word-length category. I do remember being a trifle overwhelmed by the number of novellas submitted last year. Perhaps longer ones interspersed with shorter pieces would provide variety (and a chance to read/review before the contest closes!) without overly restricting competitors?
I prefer the entries NOT be anonymous. I found I enjoyed my favorite authors stretching themselves into different topics/ratings/situations, and I was always amazed at the talented lesser-known authors that I discovered during the Games! I find that with the anonymous fests, I often wait until the reveals to really read, bookmark, and review in depth, because I like to keep track of the stories I find.
These answers are probably incredibly idiosyncratic, but as I have eagerly awaited the Games in the past few years, thought you might appreciate the views of a devoted reader!