

Maybe kinda, but it’s also a third party whose certificates are almost if not entirely universally trusted. Self-signed certs cause software to complain unless you also spread a root certificate to be trusted to any machine that might use one of your self-signed certs.
If I remember correctly, you don’t really need Prowlarr. It’s useful if you’re using multiple *arr services, but Prowlarr manages your indexers, the place *arr services look for content, and syncs them to your other *arr services so THEY can do the search. I don’t think Prowlarr itself ever looks for content automatically, only if you manually search through Prowlarr.