Hi capitanazop
I've only just started playing around on a 600D myself, but this is what I can tell you so far...
Keep the Canon menu video settings at 1080p30. You can still shoot 24/25/30 fps by changing the frame rate in the Magic Lantern menu.
The highest raw option I have is 17xx by xxx. I don't have the camera with me right now, so I'm not sure of the exact numbers. Going into the 3x crop mode (enabled in the Canon menu settings and then applied in Magic Lantern by pressing the DISP button up top and the Zoom+ button) gave me a slight bump...Still 17xx pixels wide. It was only 30 or 40 more, as I recall - the next bump up in the resolution settings. I'm sure the Excel table floating around on here with all the cameras and their raw capabilities showed something higher, though. Oh well.
Under the raw video subheading in the ML menus, press 'Q' to enter the detailed menu and select your resolution. You're saying ti's limited to 960x480 there? That would be strange, as mine lists even the resolutions I can't record for more than 1.5 seconds.