hmmmmmmmm I just added my blogspot as a domain and track the whole blog at one channel is that what you mean? Adsense > AdSense setup > Channels > URL channels add your url and then you'll be able to view your blogspot as a channel in your adsense home page.
if you could edit the html and put individual channels for every ad , that could be better and you will have more stat than one channel
Yes, and it's quite easy. Just go to "Edit HTML" and make sure "Widgets" is checked. Then you can edit all you want.