Would any of these tactics be the right move? If not, what would you do?

One guy has recently resurfaced.  He outed a couple of providers and clients about a year ago.  He seems to do it because creating turmoil is how he gets his kicks.  He has grudges but does not seem to be seeking money.  For now, he is harassing the providers--not the clients.  I suggest no Board discussion of him.  Have off board private discussions in voice with providers you know well. Do not use texted discussions or PMS.

I have nothing to hide. I'm open about my hobby to most people in my life. My soon to be Ex knows about it. Hell, I dated an escort when I was with my wife and she was more paranoid about dating then I was.

... #5 (break all contact), and then only if necessary #6.

If the other person persists then I hire a lawyer and pursue the matter legally.

...and thanks, buddy! How much do I owe ya for the props?! I can't see how that would negatively impact me.  

Not all blackmailers have something to lose, I'd say #5 IGNORE them entirely.  
There's so many new things to block them with, utilize those .
Establishing a solid hobby identity in the first place is the best way to prevent that I think, don't email from work or give personal info.  
Idk about other providers but, I get very put off if someone gives me way too much detail about themselves like workplace and home addresses. I honestly don't need all that to know you're safe to see.

If you aren't a ghost you screwed up. It isn't that tough to see ladies who don't ask for personal info. Once you have seen a few of them you can offer plenty of references. Combined with a hobby phone, hobby email, wallet locked in the trunk of the car, parking far away and walking in you can stay clear of this issue.   I am not trying to be inconsiderate, as I feel for you.  Like riding a motorcycle certain parts of this adventure are totally unforgiving of mistakes.

Over 2 Billion Clams out there, if they want you to shell out info to get the pearl, it's time to hang up and look someplace else.

For some reason this title reminded me of an escort I'd seen long ago who had a real sense of humor.  She was in the process of giving me oral when she stopped and said "If you cum in my mouth I swear I'll swallow your load and you'll never see it again."    Is that blackmail?

That would be better than if she twisted your nuts until you were black balled.