Be practical. You've got a lot invested and a lot to lose. Take time to think it through from all angles so you can make good decisions.
Bottom line, you can't stop this yourself, and EB won't care.
Of course an attorney thinks suing or threatening to sue can solve every problem... when your best tool is a hammer every problem starts to look like a nail.
You want to explain your stealth business to a judge? Good luck with that. No matter how honest you are it's going to sound questionable.
Even better, let her threaten this guy - you may find yourself explaining stealth to the IRS, along with that name variation you used for the EIN, and whatever else they SUSPECT you may be doing. Tax enforcement is known for a real great sense of humor about strategies that look like they could be used to evade paying taxes, I'm sure they'll get a good laugh out of this story! The truth won't save you from an audit.
This account may or may not be toast. I'm not sure even you are clear how much damage is already done or coming down the pipe at you.
Play for the long term. Give things a few weeks rest. Nobody can pursue this at this level of involvement for very long. His friends will get tired of messing with this in a while.
Take new pictures, write new descriptions, open other accounts and spread sales around. Pick an origin location somewhere other than where you are now.
The bitter truth is, nobody on EB is safe - ever. If this doesn't take your account down, in time something else will.
Everybody at EB has a target on their back, and the clock is always ticking. A run of bad weather that slows down packages, a bunch of buyers that give you three stars at Christmas, anything - the question isn't if you will be shut down, but when.
I made twenty accounts when I started 4 years ago, I only have ten of that first batch left.
And NEVER share any information with anyone again about what you do or how you do it, so it can't be used against you.