How to replace collum with adsense..

Great blog Kranthi..
great posts, great templates and I wish for your success..
I have a view questions:
1. For falkner press theme, can i replace tweeter box on the top middle collum with adsense?
or just simply add more adsense code anywhere i want on the theme >>how do i do it?
2. For all of your great templates, can i still edit the code>> so i can put adsense INSIDE the post?
3. Supposed i successfully put the adsense code inside the post, will the adsense be appeared on the
thumbnail (on the main page of the blog)as well? which won't look good..
or it is automatically just showing my post + picture thumbnail only?
Thanks alot.