Checked our gasser, and we do not have tow/haul either. The end of our shifter is where the overdrive is that you can turn on or off.
Stab braking -- from reading other posts, it is when you hit the brakes hard to rapidly slow say from 40/30 to keep your speed slower rather than leaving your foot on the brake for a time to reduce speed. My understanding is it will help keep your brakes from overheating. We will be mountain driving for the first time in a few months also so reading all the suggestions we can find.