it's both

it's a vote thrown away, which benefits trump, if you'd be a kamala supporter

this is so not complicated the mental gymnastics on display could go to the olympics

as for your points

1. It's mathematically impossible for a third party candidate to win, no amount of throwing away your vote will change the mathmatical certainty, this shows you did not understand the video you responded to
2. congrats, you have funded a party that can with absolute certainty accomplish nothing, woop de do.
3. Voting always does that
4. At the cost of benefitting the party you like the least... there's so many ways to do that that are risk free but instead you risk trump for god knows what reason