Okay. So the first thing to do is have zero direct contact with this person.
This ALSO INCLUDES YOUR FIANCE. Whatever he's doing, tell him to stop. Stop playing at king.com, or at least figure out how to make an account this person can't crack. Most of all, talk to the mods and figure out why his accounts have been deleted - if the mods are on "her side", then he must stop going there. I'm sure there are other, similar sites he can go to that don't have this association.
Now, just imagine you are presenting at a future court case. You say "this person has been sending me harassing emails". They will then hold up the email where you SPECIFICALLY ASK THEM TO CONTINUE HARASSING YOU. That's a major problem. You need to think logically about how to deal with this person, not just react and lash out at them.
I'm sorry, but as near as I can tell, it's unlikely any enforcement agency is going to pay much attention to this. I see no death threats. There may be an attempted fraud and some libel, but it's really hard to get law agencies to pay attention to such minor things. And like I just pointed out, it's not really harassment when you tell her to keep harassing you. However, report it anyway. If things escalate, you will have a record. Also, are you in school? Communicate with any campus security you have. Communicate with the local police. It'll be hard finding anyone willing to look at this, which is why you have to keep looking for someone who will listen to you - IF *you* feel it is a serious problem, and not just an annoyance.
If you consider this a serious problem, it's time to take it seriously. Quit shooting from the hip and do some research about the different kinds of stalkers and how to handle them. The first thing to always, ALWAYS try is giving them nothing to stalk.
That means you do not write this person. That means your fiance does not write this person. That means taking down all blogs, etc, from your site - only have the most generic info necessary to communicate with potential customers. Leave what you have up, update pricelists and photos, and THAT'S IT. Give nothing interesting for her to latch on. I understand you've already taken down the blog, so it sounds like you would be willing to do this.
Maybe, MAYBE send one firm, CALM statement. Something that, if it were read in court, would make you look unquestionably like a good guy. Then - and this is important - FOLLOW THROUGH. An example would be "I am sorry for all the troubles we've had, but whatever's gone on, it's over now. Please do not contact me again." Make no promises. Do not be emotional, do not be personal. Do some research before writing any such thing - the point is only to make it clear that you have told them not to contact you in case it comes up in court some day. And no matter WHAT they say in response, do not say anything further to them. Same goes for your fiance, and any other friends/associates you have online.
And as someone else asked, are there really 783 e-mails and messages from you and/or your fiance?
Unfortunately even just writing on this thread constitutes "contact" to a certain extent - maybe they don't know about it, but it's a public site, with her name your info etc, and would likely be easily findable with a proper google search. So, my advice, if you really want to try to solve this problem, is keep an eye on it, but ignore the hell out of it. Try to find authorities who you can go to if things escalate. Hopefully after a while of nothing to go on this person will get bored and find something else to do.
If things are as you say, is it fair you have to be the bigger person, that you have to change in order to avoid this aggressor? No, it's not really "fair", but it will be a step towards solving the problem. I guess the question is, is it more important for you to do whatever you want, or for this person to stop bothering you?
That's not a facetious question, either. My point is either this is an annoyance and you can dick around with this person, or it's seriously upsetting you (or may even lead to worse) and it's something you have to be careful of.
