There's still the cost associated with having your transaction stored forever on the blockchain across millions(?) of devices, but it's only a few dozen bytes so the impact isn't much.
Presenting evidence of a player cheating or not cheating in any form will be considered an attempt to sway the vote and will result in a permaban from the league.
...What? In what world do you not only ban people by public vote without evidence, but actively disallow evidence being shared?
You'd notice if it happened on/near your retina, it was very dark, and you were paying attention. Other than that I don't think you're going to notice.
Spaghettification is completely independent of relativistic effects; it just has to do with the gravitational gradient near a very massive body. An object near a massive body experiences more gravity on its "near end" than its "far end" which causes a stretching force. This does mean that spaghettification would be noticeable, and likely very uncomfortable as you're ripped apart by extreme forces.
Okay maybe stop now.