"the entire ab region will thicken from certain movements "
"I only use a belt when i go heavy with squats and deadlifts."
That pretty much sums it up.
Injury would probably be an issue if you squatted with your belt all the time, then was traveling and forgot the belt, then tried to squat heavy on the road, but not as likely if you use the belt all the time. None-the-less, most of your work should be done without a belt. Save it for the heavy 1 - 3 RM range.
W6