>>33,34You just provided some good criteria. Although it's risky to delete posts like if there were no tomorrow, anything that is blatant imageboard shitposting or resembles those ``ephemeral'' posts that inflate threads without much content should be deleted.
I'd start slowly with the very obvious things like ``implying'' or any other misuse of the quote function that's popular on the imageboards. It would be sad if things like the eventual bampu pantsu were to be deleted though.