You've put this in the right place. "Life sucks" is the forum to rant about any random shit that's eating at ya. Bait & tackle would be for flaming or just having fun with other members that would otherwise disrupt a thread somewhere else.
Now getting to your problem. You're right to be pissed, assuming this member was flaming you in forums that don't allow it.
Second would be the management's refusal to support your authority. I assume you don't have the ability to ban members, otherwise you would have done that.
Did you try discussing this with the admin and making sure they know the real extent of it?
As a moderator it's your responsibility to be impartial, and objective, but in return, the members need to have a certain amount of respect for your authority. Not to say they need to look at you like a cop, but they need to know that when you take any kind of action, or remind someone of the rules, you're just doing it or insure that everyone (including them) have the kind of experience that the admin has intended the site would provide.
Your admins need to realize they need to be the bite to your bark. If someone is being disruptive to the site, and undermining your authority, the admins need to stand behind you and take action. Without some way of enforcing site rules, and policy; it all goes down hill quick.