In a 2 party system every voter has the choice to vote -1, 0 or +1 for a candidate. By voting 3rd party aren't voting "For" trump you are just not canceling out a trump supporters vote. Unless you live in a swing state where the two candidates are 5-8% there is no real reason for you to cancel out someones vote with your own because there is no reason to win by a larger margin. The only time it could be a problem is if two candidates are really closely polling in your state, then you may wish to vote for the "Lesser evil" as opposed to the better candidate.That's the sole argument for voting third party instead of mainstream, in FPTP: the nuclear option. If you're willing to, for all practical purposes, vote for Trump, in order to encourage Hillary more to the left, you can Press the Red Button. But the net effect is the same as not voting. So, as far as "pushing to the left" goes, there's no difference whether you vote third party or don't vote.
Ha, thats how I feel too. Trump isn't bad enough IMO that I will vote for Hillary to spite his supports. This election is really all about Trump. Do you vote for him, against him or neutral. I have seen absolutely no reason to vote "FOR" Hillary, only that a vote for her is one against Trump.