See my second point, i.e if a person is making "spam" posts and not getting paid for it(seeing as he wasn't accepted in the last sig camp he applied to) , its not counted as (sig)"spam". And well if he keeps posting in bounty, according to the rules he just won't be paid.
I disagree with you. First of all spam is still spam, even if you don't get paid for it. While "spam" is subjective, most of the people recognize difference between useless data/info, or useful data/info. Accepting users to a campaign, even though you do not know your own rules (or try to actually fuck people over) is at least shady. They can just tell the user "Well we will not pay you as your every post is on these kind of threads", so they can just get free advertisement by method. Accepted users might think that they get paid, which encourages them to write more trash.