I just know my ad placement, isn't right, please someone help me http://www.hustlershome.blogspot.com
The placement isn't really all that bad but the color need to change. Made the background of ad same as urs and font color to your text.
I would say, put your content and ad such that when some one opens your page they should see both without scrolling.
I have seen sites with 4 adunits on them. But then, do you really want to bite the hand that feeds you? Just keep folloing the rules and you will be fine. As for your placement I think higher placed ads will help you. You should really change your color scheme because your site is difficult to read. As for the "huge change" that you are referring to on the main page, I take it you accidentally wiped out your user database?
try placing that search engine on sidebar and add a leaderboard there , and add skyscraper on both sides or a square one in between content
Cut it down so that the main page of the blog or any page with only show a maximum of 3 posts that way they have to click to go to a new page of posts and then you will get more ads If I were you I would do one ad per post