Maybe I'm exaggerating a bit, but since nowadays your email address is basically your online ID card I would do the maximum to keep it.
> If the registrar evaporates, it's still your domain.
I have no idea, I assume there's some special procedure ?
The thing is that technically it's not *your* domain, you're still renting it at the end of the day.
And no idea about dynadot sorry.
Personally, I have domains at OVH and Cloudflare