I actually had my brakes switched on all my bikes so my front brake is on the right hand side. I use both when I REALLY have to stop, but I hardly ever touch the back brake. No matter which one you use - panic grabbing can cause no end of problems but the more you work with the front brake - the more you'll learn just how far you need to pull to stop. You'll be surprised, you'll stop faster with less pull then using the back. and yes - during one of those OMG I HAVE TO STOP moments even without going downhill, I actually slide backwards off the seat so my weight is over the backtire (just in case).
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"