Got upgraded to 2.0 feature and now i can add new features, like decide which ads to use on my site, example i have sport site so ill add sports ads... and keywords, well now i dono how to really use it.

Anyone have any info about it?
Can i just add it , will i earn more?

Here i added it:
http://www.hollysport.com/index.php
Its that midle add in header.
Can you tell me if this is not against rules, i have read that there is some limit of maximum ads shown on same page, is this my maximum or im over it?

its just for referral ads, you create a referral ad placeholder and can target the ads better by choosing categories and keywords rather than relying on google crawling your page content

ahh i see, is this maybe betetr or?
Still i earn nothing from it, is it also pay per click or pay per action?

referrals are pay per action, you have referrals ad placements in addition to your adsense unit allowance to it represents opportunity for additional revenue, also you are allowed to endorse/promote referral ads, for example you could say "Firefox is the THE KICK *** BROWSER ........" Download it free of charge here - then your referral ad placement to download the FF browser with google toolbar for which google will pay X dollars per download