Now imagine this:
-bots create 10,000 accounts
-bots start spamming "great project" with 10,000 accounts
-1000 bots start reporting the other 9000 accounts
-1000 bots turn Jr. Member and continue spamming with signature
-Mods run away screaming
For now, helping one another to report spam post and the plagiarist users would be a great form of help for the forum. This could not be easily done with few users to attain a good discussions for the forum. I can be a help of this too OP do not worry tine will come that the reporting habit will make a way cleansing the forum.
Indeed everyone should report, and rewarding reporters and punishing spammers would be the best way, I think, to clean up all that spam.
Of course there would be A LOT of reports. But that's because there are A LOT of spammers on this forum. This would only be a temporary phenomenon, until all spam and all spammers are out forever.
They are here, spamming for bounties, well then, as I said in the OP, attack them where it hurts: take away their Merits so they cannot participate in bounties (as long as they keep spamming).