Additionally: Are there any good registrars that support U2F/FIDO/WebAuthn (aka hardware tokens) for 2FA? Mine only does TOTP and I would like the security provided by hardware.

Namecheap does: https://www.namecheap.com/support/knowledgebase/article.aspx...

https://TakingNames.io obviously. Disclaimer: I run it.

I'm curious what goes into running one? Do you need to have stable NameServer's with static IPs that have 100% uptime? Why create one?

It's very easy to get started, and easy to progressively add services.

The most important distinction is between a domain registrar and a domain reseller. As far as I know, most start out as resellers (Namecheap started as an Enom reseller. AWS still resells Gandi). Being a legit registrar is actually fairly expensive.

Reselling complexity depends on the upstream registrar. Most of the big ones have reseller programs, including white label services. TakingNames.io uses Name.com, which doesn't require anything official. I just sell domains using Stripe for payments then use the Name.com API to buy the domain. Then I forward DNS changes using their API as well.

Currently I default to using Name.com's nameservers, but users can set custom nameservers and I may run my own eventually.

I use Porkbun because they're typically the cheapest, tbh. They have a really nice interface too, but my registrar isn't something I interact with more than once a year typically. As long as they aren't shady like GoDaddy, it doesn't matter that much. There's tons of good options.

+1 to Porkbun. I think cloudlfare sells domains at-cost so if you want something cheaper than they might be worth looking into.

But I have been a happy porkbun customer for a few years and they are my go to recommendation to anyone who asks.

Also have quite a few great easter eggs on their site. Always nice when a company has a bit of personality.

Porkbun has been good to me, but I can't get it to work for iCloud custom domains.

porkbun.com is great