When I first started riding again a few years ago, I had a Giant Rainier. No matter how much adjustments were made, if I let go of the handles for any length of time, it would start to shake and I would be down.

Two years ago I changed to a GT Peace 9r Multi and from day one I could let go, sit up and pedal. I could ride all day with no hands now. For me it was the bike Not to open up the safety zealots, but I have from time to time, pulled out the Blackberry and fired off an email or text while peddling

As far as the twisting to look back thing. That is a technique that keeps the bike from veering into traffic or off course. If you hold the bars with both hands and just swivel your neck, you will have a natural tendency to veer the directing of the neck crane.