As far as I know, there is no way for me to download all new posts. Only Newbie's posts show up in patrol.

I make my threads self-moderated (turns out I couldn't do that in Meta). But it doesn't work if the topic starter doesn't care, I've seen self-moderated threads with hundreds of pages filled with spam.
In a self-moderated thread you can use your middle-mouse on the delete-button. This opens a new tab, and deletes the post without popup asking for confirmation. This is a very fast way to delete spam.

This is the worst part, which I've noticed too. It's one thing if they pollute the Altcoin Bounties and Off-topic boards, but reading their spam on the serious boards is much worse.