If Adsence CPC for a certain word is 30$ does it mean it'll pay me 30$ per click? Or how if not what's the percentage of this amount it'll pay me?
No. And this information has never been publicly disclosed. And you should know there is a content network which advertisers can opt out of. If they do then the ads only appear on Google properties and contractual sites not on mom and pop adsense sites.
check the stats of your web site's traffic, especially this page ;-) http://www.internetmarketingiq.com/category/pictures
We don't know that, but that isn't really important, the important stats are traffic related, the rest will come
That's pretty interesting to know, too. The same as there are clicks that cost even more than $100 per click.