… I would just like to be able to view it on other computers or DVD players at the original quality.…
a DVD is 720x480 and highly compressed.
… how to export a pixel-for-pixel, frame-for-frame replication of what iMovie apparently effortlessly displays??
video is compressed - otherwise, files are getting gargantual (a top-notch intermediate in FCPX is 40-120GBs per hour, a disk, for comparrison is 4GB/h).
• in the Export with Quicktime Option, you'll find a bit-rate setting - depending on your other settings (resolution, framerate, codec), 5-10.000 kbps should result in a superb result.
• instead of a playback-optimized codec as usual h.264, you can give AppleAnimation a try - much larger files, but e.g. less banding. only for use on Macs.
to transfer lossless to iDVD, choose AppleIntermediate, which is iMovies internal codec.
.... but a disk with same quality as a computer HDef? Not possible.