The problem with wheel bite is that it tends to stop the motion of the wheels. This can result not only in a bad wipeout for the rider but also damage to the wheels. With the help of the riser pads, it is easier for you to preserve the deck of your skateboard since these pads can reduce the tendency of having stress cracks on where the trucks and deck meet.
There are other types of ollies that you can do either alongside or combine with the ones listed above, like the tailgrab, indy grab, melon grab, stalefish, tweak, and dolphin nose. All of those skateboard tricks are performed more or less how they sound, but you might want to watch some videos on youtube to see a pro in action (as well as awesome cat videos).
To get higher ollies, I would suggesting resting your back foot on the very end of the tail and the front foot in the middle of the deck to allow for more slide. Popping as hard as you can and catching your board in the groove of the nose with you ankle practically resting in the groove will level the board out in the air. after this initial movement slide you feet back to the bolts on the tail and nose to ensure a clean landing.