Overall a solid improvement. More polls will help a lot, assuming enough people vote, which appeared to be a problem in the prelims.
Thank you regarding the OP/ED change. Very wise choice. I had actually assumed that it was by both animation and music before voting. Now that I understand that interpretation was wrong (but will be correct in the future), people's voting patterns for OP/ED make more sense now.
Best Seiyuu
I have a feeling best seiyuu will be a bit troublesome for a category, since I don't imagine most people really keep track of that. Especially for newer fans this will be difficult.
While I see the problems with "best character," I disagree that "best seiyuu" is "essentially equivalent" to best character. A lot of things that go into a character that have nothing to do with the seiyuu, character design for example. Then there's the writing and plot behind the character that drive its development. While that gives the seiyuu something to work with, they're ultimately voicing a character created by someone else. A good example is Ogata Rina from White Album. Absolutely fantastic voice work by Mizuki Nana. Her brilliant voice acting really made Rina shine, but I would never vote for Ogata Rina for best character.
I have some doubts, however, that people will do a good job differentiating characters from their voice acting. But we'll see. Maybe I'm just being pessimistic. It's also not clear from the title category that it's just one seiyuu, rather than all of the seiyuu in the show. A little bit of text could probably resolve that ambiguity, at least.
Another problem is that some seiyuu can be great as one character, and be awful as another.
http://boards.fansub.tv/?showtopic=10137 Dragon crisis is a good example of this. Kugimiya Rie, as you mentioned, is well known and generally acknowledged as a skilled voice actor. She did a great job as Alphonse, Aisaka Taiga, Gintama's Kagura among others...but as Rose in Dragon Crisis, she's just annoying. Not particularly fantastic as Hysterica in Dance in the Vampire Bund, either. Given that Seiyuu often take on multiple roles in a given season, some of which could be good, and others mediocre or downright poor, this is quite a problem.
Category Overlap
You mentioned overlap between most original and best plot. I think "Most Original" could have been salvaged by changing it to something like "Most Original Setting" or "Most Original Characters" to make the difference between the category and "Best Plot" more clear.
Actually I think one of the more major sources of category confusion was between "Most Enjoyable" and "Best Show".
While there is a difference (I might not personally enjoy Giant Killing, for example, but I have to concede that it is very well done) the two categories are very similar, and may require some additional instructions to differentiate:
In the preliminary round, there were 70 overlapping votes out of 134 total nominations for both categories. By overlapping votes I mean votes where the same person chose the same series in both categories. In other words, on average
more than half of the time, if a person chose a series for "most enjoyable", they also chose it for "best show."
more than a third of voters had 100% overlap(6/17 voters) between best show and most enjoyable. (Including people who omitted some from one of the categories, but did not choose to vote for additional, different shows.)
If "most enjoyable" is really supposed to be a "guilty pleasure" category, for series that people don't genuinely think are high quality, but still enjoy, why not just make it that?
