You mostly answer your own questions and thus leave me little to add, but here are a few points.

What of using the zerohedge logo?

I'm ok with it, as it helps get attention to the posts themselves and he's clear both in profile and posts that he's not Zerohedge.

they see @zer0hedge believe it's authentic and upvote without reading the article itself.

Then maybe we have bigger fish to fry, such as fixing the incentives.

I can respect your opinion about copyright without downvoting your perspective, although we disagree.

That's entirely up to you. In cases that I downvote something it is sometimes specifically because I do not respect that particular opinion.