yes that is allowed you should read this https://www.google.com/adsense/localized-terms good luc PeAcE
Yup. You can even add one more Google search (max is 2). How old is your site? I believe you may increase the number of ad units as you get more traffic, not sure.
Sure you can do it, Adsense allow you to put 3 ad blocks + 2 link unit and 2 search box in your site. But 2 ad block + 1 link unit are the best way ( too much ads block will reduce your bid rate )
Nope you're wrong! only 2 ad blocks + 1 Ad unit + Adsense Search are allowed, else you still put more blocks, they wont apear on your pages, so its useless.
Both of you are wrong Maximum blocks on one page - 3 content ads blocks - 3 links ads blocks - 2 search boxes
Have maximum content and minimum ads and let them blend with your contents so that it increases the CTR. Too much ads will distract the visitors.
Enough BS, Here's the real deal... Up to 3 ad units may be displayed on each page. A 'maximum' of 2 Google AdSense for search boxes may be placed on a page. Up to 3 link units may also be placed on each page. Up to 3 referral units may be displayed on a page, in addition to the ad units, search boxes, and link units specified above. AdSense for search results pages may show only a single ad link unit in addition to the ads Google serves with the search results. No other ads may be displayed on your search results page.
You can only display 3 Ads Unit on every pages.. Having more than 3 ad units cause some ads not to show correctly.. And the more ads unit on every page the lesser conversion you get from every click..