Domain and account setup best practices for non-resellers

Would there be any advantage/disadvantage to setting up the DA server using this domain, and then giving it the hostname web.acme.com?

Best is not to use default names for hostnames, so no mail or www, imap and such, could give troubles later.
However, web is not a default name so yes that would be possible. The hostname doesn't really matter, you can also user server, srv1, vps, my or whatever you like.

I don't use Cloudflare DNS, but if you would like to switch to your own nameservers later on, then it might be easier to already have the correct domain in use.
For example if I would have acme.com and I plan maybe to later on use ns1.acme.com and ns2.acme.com then I would use web.acme.com or server.acme.com as the hostname for example.

If you rather use acmehosting.com for your nameservers, then I personally also would use something like server.acmehosting.com for the hostname.

Benefit of running own nameservers? For sure.
You don't have any fuzz with external nameservers, all options can be done via DA. Next to that, no issues with automatic SSL certificates, no need to configure LEGO, this all works automatically.

Be aware that some registrars do not accept the same ip for 2 nameservers, so in some cases a secondary ip is required or a cheap vps with for example Directslave running as secondary nameserver. It all depends what you want.

The reason for the hierarchie is safety. I wouldn't set every domain under admin unless you're the only customer on the server.

Best is only admin, with admin domain, and use a reseller account for the customers. Or multiple reseller accounts, which might make transfer to other servers later on (if needed) a bit easier.

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