I like to suggest to open a service discussion for how a campaign must be managed in a right way
There is no right way to manage a signature campaign, as they aren't regulated. To think otherwise is very stupid.
- What are the selection criteria / how much important past post history
It varies every campaign, and depends on the manager. Spam campaigns like YoBit and secondstrade won't care about past post history. Generally, they look for members with a good post quality though.
- How a spread sheet must be maintained
Again, there is no right way to maintain a spreadsheet. Does the manager of the campaign not manage it the "right?" way? Join a different campaign.
- Why trail basis are not given commonly
If you were the owner of a restaurant and needed to hire cooks, would you rather hire one that has good experience already, or would you hire one that might not cook very well, or has no experience? Would you be even willing to risk hiring a really bad cook? Probably not.
- Why some threads are marked as spam and why some sections are is not included regardless of gambling /altcoin campaigns but for same campaign manager.
Because those threads are basically people echoing each other, and has no value. Some sections aren't included since they probably aren't good for advertising, or have spam. Would a fully english dice site want to advertise in the French section? No. If you ran a restaurant business, you would want to advertise to people who eat at restaurants, not people who insist on cooking everyting at home. Again, if you don't like the terms, don't join.
There are many campaigns to chose from. If you don't like a campaign manager or how it is managed, simply don't join the campaign. Most people that complain are probably those rejected from good campaigns because they have bad post quality.