Concentrate on getting the meat right! No amount of sauce or rub will fix lousy meat.
Don't go changing your seasonings too much - most cooks find that trying to get the "local" flavor costs them. Hit a middle of the road on heat - go heavier on the sweet!
Even in Texas, BBQ judges don't want the taste buds burned out on the first entry - they WILL NOT reward you for hot & spicy!! Trust me, I'm one of them and we talk about this a LOT!
I've never had ribs too spicy (and I know the difference between spicy and hot!) but I've heard a lot of judges complain about too much heat. A nice kick is appreciated - consistent burn and the need for a glass of milk before the next entry is NOT good!
Just my $.02 worth. And yes, I lived in San Antonio for 9 years and have an appriciation for Texas BBQ and all things spicy. :D