> You mean requiring SQL software, or just making backwards-incompatible changes that would screw up old threads?

I mean, needing to alter the table that is already in the database. I don't want to try to do that any more than I have to, as it's pretty hard to get right in a database-independent manner.

> Are you only referring to flooding and spamming, or also trolls and flamewars?

Yes, only flooding and spamming. Trolling and flamewars are not a problem one should use banning to try and solve.

> Finally, out of curiosity: how much of the functionality in the .js file do you think could be properly implemented into a new or existing perl script?

Well, if you serve up dynamic pages, you can do the form-filling on the server, but that's about it. The rest is dynamic stuff.