1. Changing link attributes for the left sidebox ONLY. (It has no ZC elements...but a collection of links that I have put together independently.)
You should look at the modules in the downloads section either or both the About Us and the Blank sidebox contributions. Or alternately ezpages can provide for links in sideboxes.
2. Making the tagline go "above" the top nav bar. Right now the tagline overlaps with the top nav.
Rather than post the code here again you can search for this here or I believe that there is a module in templates download area just for this.
3. Adding a Business name at the top to the right of the logo image in left top corner, i.e. I would like the business name to appear at the right of the image and flow toward the right end of the page.
If you are not using the "tagline" currently, you could adapt this for the business name and then re-locate using the css styling.