Once a thread is taken over by spammers, there's not really any easy way of recovering it. I have not really ever seen that being done either.
Again, there are internal discussions regarding this matter. I have compiled a nice list of threads that need locking and trashing (preferably). Once there's some consensus on the matter, it will be (hopefully) handled.
The "farmers" that you refer to whom I was talking about are mainly of a lower rank so they may be looking at making many posts to get accepted into a signature campaign once the account matures.
Not necessarily. It is not rare for me to see Hero member accounts (with or without signature) who almost have no clue about Bitcoin (i.e. their posts lack in content and quality).