I just found out that wall messages still show up on the public news feed for everyone to see, which means that I cannot discuss movie spoilers here. :(
I can answer questions 1 and 4 though:
1.) Yes, one of the highlights of the movie is that it shows an epic combined fleet combat, fully animated with ultra-high budget 2D HAND DRAWN animation, with a few top-tier 3D CG animation. Yes, you've heard me right. :)
4.) Same with night battle; the movie shows a gorgeously-animated night battle sequence, complete with star shell and searchlight combat.