Hello,
to address your concerns:
1. No, each participant only gets one vote per game.
2. All of them have demos/free versions available for download on the game's page as far as I am aware, if you find entries that do not please let me know and I'll deal with them promptly.
3. There was a large volume of unrelated games submitted to the jam and they have all been manually removed.
If you would still like to submit your game to the jam, please upload it to Itch and I'll give you single-use submit link.