Here is a link to the spam and banning tutorial, https://community.socialengine.com/blogs/597/33/spam-and-banning-tools . 

I created a Banned member level and put members in that if I don't want them to have access. In that member level, I have everything set to No for posting, profile viewing, etc.

As for deleting, when we had 15,000 spammers sign up here overnight a few years ago, we had to manually delete some of the content. So, if you delete the user, just check to ensure the content deleted. It might not if someone else posted on it, etc.