A: Depends. I hope that solves the controversy.
Just in case you need a more detailed argument; Despite what doom-sayers might want you to believe, a fixed gear bike without coaster or hand brakes can stop just as quickly as any bike equipped with those slowing-assistance devices. That is, if the rider knows what he or she is doing. Experience and practice is the key.
The problem is then that anyone with the cash for a fixie can buy one and hop into traffic with nary a clue how the thing works. In my time commuting by bike in San Francisco I’ve been hit from behind three times. All three times were by fixies with new riders.
So what’s the solution? There isn’t one. What we do need to do though is blame the rider not the bike. If someone runs down a pedestrian in a crosswalk, it’s the rider’s fault, not what they were riding.