Anti-Spam/Leeching Suggestions

This topic has been pretty much done to death, but it's well known that leechers and spammers get on the community's nerves. They don't really care about the site and are incredibly hostile if you call them out on it. I understand that even if there are limitations, you can't stop a leecher completely. If someone wants something on a practically public site, they will probably not stop until they get it. Here are a few of my suggestions to mitigate spamming:

• Limit the speed at which newly registered users can create new threads.
  
• Create a feature built into Cuddles which notify staff of (relatively) new members with unnaturally quick posting activity, which could be disabled per-user.
  
• Check if there is at least one (or more) word that actually exists in the dictionary within new users' posts.
  
• Prevent users from copy+pasting the same thing into multiple posts within a relative period of time.
  
• Prevent users from posting content that only contains quotes.