How do you know when individual seeds have downloaded the complete file and are not just seeds at, say...5% finished downloading? Or are seeds, by definition, people who have already downloaded the whole file? I'm given just two hours max on the computer(public library) before it reboots and deletes everything, except for the programs the library has on the computer. Is that enough time to get 'complete' seeds on something like a new popular movie? Is it possible to continue seeding after reboot as long as i brought along storage to keep the torrent/'torrented' file on?

Oh, and even still, if the answer to my last question is yes, how will i know when someone else has the full movie so i can be relieved of seeding duties(the place isnt open 24/7, & I aint tryna be there all day anyway)?

Seeds become peers when they have downloaded 100% of the file and decide to stick around instead of letting you continue to upload. You should invest in a seedbox if you want to really get results. It depends on your internet connection on whether or not you can get someone the file within that time period. As long as you have the actual torrent file and actual movie file that the torrent file uses, then you can seed anywhere.