Buddy, its not really possible to automate a bounty campaign. Because I am pretty sure bots wont be able to check the post quality of a member. I am not saying you cant automate bounty campaign. Yes you can. There are bots for that purpose. I have seen that type of campaigns . You, please check in the service section of this forum. But even if you use bots, campaign manager has to check the post quality of all participants to prevent spamming in this forum.
Signature campaigns of course can't be automated.Post counting,post length counting could be done but the post quality,never.That's why Campaigns use a manager along with a post counting bot to keep a check on the quality.
Apart from that,twitter,reddit/other social network campaigns could be fully automated.