this is just some questions to plan ahead. it doesn’t involve a real scenario (yet)
Lets say I have 2 devices: 1 complex web server with email, dns and everything and 1 more simpler webserver with just web
of course I want both to offer secure services, so both should have certificates
my question is: could i get a wildcard *.mydomain.com certificate for the main server and then another cert for the simpler one like testserver.mydomain.com ?
also: can i adquire both using the same email (the webserver LE creation page on my control panel asks for a register email)
It can be deleted immediately after getting the cert, but you will be required to create a new one (with different contents) every time the certificate is renewed. It’s best to automate this using a DNS API.
Yes, the original DNS entry is no longer useful for any purpose after it's been used, but a new one is always required to confirm your continued control over the domain name.
It looks like it can do it for you if Plesk is already set up to manage DNS for the domain: