beardy wrote:Finally if I am going to get rear ended, I dont want to stop the car that is hitting me too quickly.
The handbrake will let my car move quite a bit further than the front disc brakes would, which lessens the force of the impact.
Also hillstarts are very challenging without the use of a handbrake.
You are missing the point about the handbrake. The point isn't to stop damage to your car, it is to protect other people in front of you. If you are, say, stationary at a junction or lights, and have the handbrake on rather than the footbrake, your car may well suffer more damage. Few people would react fast enough to use the footbrake, and in many cases the impact would cause your foot to come off it anyway. But if you don't have it on, you will move (or move more,depending on the force of the impact) forwards, pushing you into the car in front or the pedestrian crossing in front of you, or into the traffic crossing the junction. Or may push a car or cars further forward and cause them to do that.
I've been rear ended when stopped at red lights, I had the brake on, and though my car was damaged, no other cars or humans were. Which I think is the right result.
In a car, a mirror could help avoid a rear-end if the road in front was clear and you could speed up to give the idiot behind more time to slow down, but on the bike I for one can't suddenly speed up enough to help. And judging speed of oncoming traffic in a mirror is much more difficult on a bike mirror than on car mirrors.
I do think it's worth having a mirror on the bike if you have somewhere to put one, but you do need to be aware of their shortcomings.