How could These Agreements be governed and interpreted in accordance with the laws of Hong Kong, while online gambling is not allowed in Hong Kong? Does this make sense?
It could be that the operators of Betcoin are channeling their funds through a Hong Kong registered company for tax evasion purposes. Companies registered there pay zero tax on income earned from outside Hong Kong. You are right that online gambling is illegal there so they would be laundering money first by passing it through intermediary companies or payment processors which are all outside HK. If they are doing that it seems to me to be a pretty dumb thing to do to reveal that in their terms.
You do not have to funnel Bitcoin transactions through a registered company, as it is a decentralized and anonymous system. Furthermore, Bitcoins are in many jurisdictions not considered as a currency and therefore no need to register a company in Hong Kong for tax evasion purposes.

If they would have a shell company in Curacao, then this would be sufficient enough to avoid tax payments.
Without stating the contract partners and the provably applicable jurisdiction, there are
no juridical valid Terms of Service. Simply call their "Terms of Service" a fairy tale.
Is the company who operates Betcoin.ag incorporated in Curacao and holds a worthless Curacao eGaming license?
If this is the case, what is the name of the company? Why is the name of the operator not stated on their website?
If Betcoin.ag has a valid license, why do they not state the seal on their website?
Betcoin is in the business of offering gambling services to Americans, so they have been very careful to not reveal the associated company names.
Bs at its best!
First of all, the problem is not offering gambling services to Americans in non regulated states, the
money transfer to and from gambling companies is prohibited.
Secondly, there are several companies licensed in Curacao and offer gambling services to Americans and also state the name of the operator and the license seal.
All through their terms they just refer to themselves by domain name as a proxy for "we", "the company", "us" etc. Their domains, owned by a Stephen Lee, have all other info privacy protected. The domains are routed through cloudflare which hides the server's IP address and location. They aren't going to give you a company name because the operator does not want to be found.
I understand perfectly that the operator does not want to be found.

There are many, many online casinos that state that they are "licensed" by Curacao or Costa Rica or Belize or myriad other places when in fact they only own a shell company and host their website there. In many cases the jurisdictions (like Costa Rica) don't even issue licenses for operating an online gambling site. The Curacao statement in the terms is an indication that they are probably hosted there. As you say, Curacao eGaming does issue licenses but sites that have one almost alway display a linked seal on their website. I can't find one of those on Betcoin's site. As far as I can tell, Betcoin is not licensed to operate an online gambling site by anyone, anywhere.
No. It is not an indication that betcoin.ag is hosted in Curacao! You can not host a gambling company in Curacao without having a license there.
The sole intent of the Curacao statement (there are no Terms of Service) and the Hong Kong statement about governed by bla bla, is to mislead potential and existing customers. They imply that betcoin.ag would be governed by authorities and that there would be a "legally binding agreement" with the possibility to claim and enforce your rights, while in reality there is nothing,
zero point zero!