The quality will vary depending on the photo and the crop. For instance, on our recent DLR trip, the images provided by California Screamin', ToT, and Space Mountain all were 3840x2560 in the original format. However, if you edit the picture by cropping it, the size will obviously go down. I believe the older Photopass cameras had a 6MB sensor, so those source photos would have been similar in size. Can't recall what they are shooting with now. Hig h Res basically means that they won't down sample the image any. So you can get prints with it, where a "Low Res" image is one that might be suitable just to post to Facebook.
The limited license document is just their legalese that says you can basically make prints of the image for non commercial use. You can't sell it, or use it commercially in any fashion. So as long as you were just getting the download so that you can make your own prints to hang on the wall, stick in a digital picture frame, use for the holiday cards etc you will be fine. Some photo processing places will refuse to print pictures that they think may have come from a professional photographer unless you have a release to prove that you can make prints. This keeps people from buying one copy of a wedding photo, scanning it, and then making prints to give to all their friends instead of buying them from the photographer.
