Changing excerpt to content on category archive posts?

I have tried changing the excerpt in function.php to content, and it causes the formatting to be whacky (no breaks between paragraphs, for instance, and the teaser posts on the front page begin to pick up text from the post rather than descriptions). I have the front page how I like it, except it does seem the teaser description is slightly cut off.

However, when you click on any archived category posts, you get an excerpt and have to click again to read the entire thing. I find this a little annoying, but don’t know how to fix it with this theme. I’m not very good with css, but in the past have just edited the_excerpt to the_content in either a loop.php or archive.php file, neither of which is seen on this theme. And I don’t want content on the teasers on the front page, just on the archives. Is this possible?

site in question: moonwillowpress.com. Thanks for the otherwise great theme!