Nope. You're going to have to put up with him/her. Forum doesn't have the functionality built in, and the aftermarket solutions I've looked at are pretty clunky.
Would be a great idea. If your referring to the individual i think you are,its simply best not to encourage trolls by reacting to their antics. Eventually if people do not react to a trolls statements & provacation attempts,the would be troll will lose interest in the subject & people -thats the theory anyway. In my time here & other forums,from what ive seen these personality types come and go pretty quickly,give it a month or 2 & itll pass.
Who is saying all this? *looks around for source, realises has inadvertently switched on "ignore" button in brain. Happens a lot these days. Age-related.*