600d RAW music video shooting

[Vanx]

Hello guys, I'm testing RAW on my 600d with latest ML Nightly build.
I have some questions..
I usually shoot my own music videos in video mode 25fps, and in fcpx I use black bars to get an 2.35.1 look, so I like the "cropped" aspect.

I found that for the 600d 1152x432 in crop mode is the maximum resolution to achieve consecutive recording (I need it), I simply grade the dngs in LR and edit in Resolve 1080p timeline, is this any good? I can't understand what crop factor I'm seeing by doing so, but It isn't bad, I wanna understand if I should do like this or it is better to stick with h264 1080p and black bars.
Do you think that this aspect ratio is funny to look at for a professional music video? I use 50mm 1.8 and a 24mm 2.8

1) To shoot at 25fps, do I need to override the fps settings in ML and set 25fps for raw?
2)If I exceed the 4gb limit before finishing a song "take", will ML automatically start a new .raw file (to be combined in post) or will I get a frame stop between the two files?
3) is there any way to get a zoomed LV preview while shooting to make it easier regulating focus?

thanks ! (I'm sorry if I asked simple questions, I read a lot but.. I hope you'll understand)