...10 post on gambling sections mandatory. Which might increase spam and you might get low quality post...
I don't think so. 10 posts are not much because is only 1,5 a day and even if then the manager will remove such a spammer.
If there is a lot of spamin the campaign the only person to blame is the manager which allows that to happen. I am sure we have a decent manager and he will filter all spammers out of the campaign.
I also can't say that 10 posts per week in the gambling section are categorized as spam. As long as you make a post have a distance of each post, meaningful, and not out of topic. I think that's normal for gamblers and people who usually make posts in that section. However, it is clear the Rules & Requirements say "If you don't regularly post in the Gambling section, Don't apply."