They would need to register with the Financial Crimes Enforcement Network (FinCEN) once they are being transacted like a new convertible virtual currency
Why? Is Bitcoin registered on FinCEN? Seriously...

Your questions were already answered in the article.
If you care to read it again (this time with comprehension), you will find that Bitcoin, being created by the anonymous Satoshi, has no principles for FinCEN to have jurisdiction over.
On the other hand, Classic is being created by identifiable individuals, many of whom live in the US and other NATO/FACTA countries.
Please learn to read more effectively, and stop misleading people with such trivially debunked fake 'gotcha' questions.
The essay was written by an actual lawyer. You aren't a lawyer, you are just some stupid-as-shit Gavinista that isn't even especially literate.
The only reason you're straining at the article's well made points is that it's not pro-Classic.
But the essay is factually grounded, and pretending it's all just a big lie won't help Team Classic when the TLAs come knocking.