So I wasn’t sure if Child Themes was the answer in this particular situation since I had already edited alot of the twentyten template files and those would still get overwritten in an upgrade. So…I think I might have found a different solution.
First, I changed the template name in style.css and theme directory name from twentyten to twentytenchild. Then I went into wp_options and changed the options for "template" and "stylesheet" to twentytenchild. This seemed to do the trick. I downloaded a fresh version of twentyten and dropped it in my themes folder, activated it and then re-activated twentytenchild and everything seems to be fine. The fresh twentyten theme seemed to be pulling in styles from my new stylesheet (not sure why that is happening), but since we won’t be using twentyten, this isn’t a problem for me.
Any SQL/Wordpress wizards out there know if this might not be a good solution for some reason?