You have some nice stuff.
But I think you may be making a mistake making this out to be case of persecution. It's a competitive move by a competitor and you should be responding as such.
Let's look at the individual complaints;
copies everything thing I do, buys huge quantities of stock which I can't afford to do and then undercuts all of my prices
That's legitimate competitor behaviour by a copycat.
he has changed his 3rd user id to westernstargift (which he has used in the past) and has listed many of the western themed products that I list. Even his avatar picture is almost identical to one which I recently used
Also, not a technical breach of ebay rules.
He copies my titles, my styles, my descriptions as closely as possible
As long as they're not an exact copy, there's nothing you can do and you know that.
He recently sent me another email telling me to watch for "new and exciting" marketing stategies
You don't have to read his emails.
Apparently he can do nothing on his own
That is his mortal weakness and the point on which you should be competing.
Some suggestions;
1. ebay isn't the only game in town - branch out. It'll take him time to find out where you've gone and he may be unable to follow you there.
2. You can innovate - he cannot. You have a huge advantage - I've never worried about copycats because, by the time they figure out what I've done and how to copy it, I'm starting something new. They are ALWAYS 2 steps behind me - in the jewelry business, where the latest thing is what sells, that can be deadly. Compete on YOUR terms, not his.
3. Stop looking over your shoulder. He's always going to be there, but that always means that he's going to be
behind you. Use that. Concentrate on your business, not what he's doing.
There will always be copycats - there can only ever be one original.
Imagination will often carry us to worlds that never were. But without it we go nowhere. Carl Sagan