I looked at the terms / rules and the best my non-attorney mind can understand is that they are normal and expected in that they limit their usage of images to the promotion of the event.
However, I did not see (or overlooked) the mechanical requirements of images entered, and that would be my only caution.
Over the past month or so, I received two invitations from organizations to enter two juried competitions. However, upon investigating both I discovered their mechanical requirements necessitated uploading of publishing-quality images.
One required submission of a 300 dpi file with a measurement of no less than 10 inches on the shortest side. The other required the image at it's full, native camera resolution. I decided there was no way I was about to release high quality, printable images out there into the wild.
If this contest has reasonable / customary mechanical requirements (i.e., 1000 pixels on the longest side) then I might think it looks like an ok event.