SPAM control for podmins; could someone summarize please?

I have tried to search for a place which actually summarize what antispam possibilities a podmin have.

So, I have seen several threads, most of them from many years ago, mentioning various spam problems:

  • how to control spammy registrations on the pod
  • how to control fake email for the spammy accounts (how not to send email with unverified addresses)
  • how to control connections and content of spammy pods
  • how a podmin can destroy a spammy acocunts’ contributions (posts, comments, likes, whatever) apart from closing the spammy account
  • is there any way to control actual spam by registered accounts (eg. rate limiting, watched keywords, etc.)

(This question was partially arisen by spammy local registrations, and partly due to public post relays.)