Not wishing to sound over critical but as I opened this post and just the list appeared (not the poster) My first thoughts were . OK another newbie using a survey to highlight his recent entry into the domain market. I'm not going to vote for any because I think you can do far better by just a low to reasonable spend in the after-market
Great input here from many.
The target audience is of course mainly to the business owners who may need a platform on which to collect personal info and payment for people who book.
As we are domainers, we also WANT people to have their own domains, so the platform should be designed to federate using booking widgets that run on your own site.
So, if you own ABC.com, we don't really need to send you to a site where you can book 10 other things. It should be painless to let folks book right on your site.
The key for consumers is (1) secure and efficient transaction processing, (2) central dispute resolution, and (3) convenience of having saved preferences.
In other words, the experience should be federated but interoperable. This is the opposite of EventBrite, OpenTable and similar centralized models.
Add the overlay of being able to settle in crypto, and we have a candidate for a booking platform for the Decentralized internet but still using domain names as brand identifier.