I have been using porkbun.com as a domain registrar.
For email hosting, self-hosting is a lot of effort. If you just want the damned thing to work. I've heard good things about Fastmail, and personally I'm using migadu.com. it's $19/year for micro.
Use any imap client, or if you want to keep using what you're using Gmail and Outlook and Apple mail apps w all support your new personal account over imap as well
Their own doc, sure why not.
Any other context where there's a giant with the same name. No, please at least write it out expanded once.