Well I figured it out... It was indeed a problem with my manifest.xml file. Anyway, I'm glad I decided to spend the week building this. I've already learned so much about how to use git, c++, and a bunch of other invaluable skills from this little project.
Getting back on topic, this first build (if it works) will only be for us gt-p7510 users. After that, I will start work on the other galaxy tab models.
Cross your fingers.