Solutions for frontpage that consist of only blocks
The pages are already built from blocks, where the 'main content' block is the page content. These blocks are positioned in regions defined in the template. 

I guess you want to reorganize the blocks? Have maybe multiple columns and so? Then you can either use panels or alter the theme with the regions you want. (This basically is what panels does, but at the position of the 'main content block'. Leaving the other blocks intact.)