I REALLY wish the admins would sticky my post:
HOWTO: Alternative Root method for Samsung Exhibit 2 II 4G with a Read-Only filesystem and no su
I was having the same problems. This link will take you to a method I figured out to keep the phone the way it was when you bought it, only rooted. I joined the forums just to share this with everybody, but nobody reads it because its buried beneath the rest of the post asking for help or telling about zergrushroot (which no longer works with newer models) or simply telling them to flash the entire phone with a custom rom