New Blogger-theme help and can I do this?

Here is what I need in a dream blog

Simple design to add my own colorful images
able to upload my own header or logo
able to upload adsense
4 collums
wrap around text in the articles

Here is what I need to know about altering pre exsiting themes:
Can I change colors in tabs and rules?
Can I put my own header?
Can I add adsense?
Can I wrap around text?

There should be more notations on the wordpress themes….and style numbers!
1.
as you ARE LOOKING YOU HAVE TO TRY AND REMEMBER WHICH ONES YOU LIKED AND WHAERE THEY ARE.
2.
You do not know what you are capable of doing–can you change this or that? Add whatever.