Post Title size and Line spacing

http://www.inspiredraw.com. Atahualpa 3.2. (sorry that it looks like i've put this in the wrong section).

Post title size. I would like to make the post titles smaller. Based on other threads, I went to Post/Page Styling and added the font size to the Headline Box: Text and Headline Box: Link areas:
padding: 0;
margin: 0;
color: #009999;
font-size: 1 em;
font-weight: normal;

I was able to turn off the bold, but no matter what # I put for font size, it seems to stay the same.

Line spacing and look. I assume there is no way to use maybe a 1.25 line height to open up the text a bit? The blog feels crowded to me. The wide right sidebar doesn't help, but I had to do a lot of customization, so IE wouldn't mess up the boxes. I'm now therefore afraid to mess with it!

Also, is it looks like the body background in the light teal "cuts across" as a bar under the custom header. Is this because my header isn't all enough or is this area something different that needs to be given a white background. Looked around and couldn't find anything.

Thanks for help!
Caryn