i have exported files as hi rez jpegs and also pdfs and it has worked well.
I think if you use iDVD you have to use one of their templates. But you should be able to tweak those pretty well. I’ve personally bene able to do a lot with those and just drag and drop video or images into the windows to create my own presentations. IF you want anything more , you have to go to a program like DVD Pro in order to have complete creative control.
I usually export DV content using “Export as Quicktime Movie” and select DV-NTSC48K. Then you can just choose import in iDVD to bring it in. IF the video is too large to bring it in as DVNTSC 48, then maybe try the Apple’s Compressor 2 (if you have it) to limit the file size. There’s many option there.