Even if you skated on real or imagined legal issues

Seems like pretty clear-cut freedom of speech to me. Plus, you could plausibly claim that you weren't even referring to anyone getting killed -- just with Kirk's death, you now have a shortage of conservative pundits and need a replacement, so you want them to send you more.

Though, I suppose it could technically count as vandalism to put the sign up without permission?

Anyway, yeah. It's the randos you really need to worry about.