There is no doubt that motorbikes are more vulnerable than cars to certain dangers such as being less visible due to their size (or lack of it), and once you lose control you have much less chance of recovering it (thinking here of a skid on diesel or ice), and if you do happen to have a collision then the consequences can be so much worse.
The positives to come out of that is that you become much more aware of hazards like ice and diesel; and you have to concentrate more on the task in hand. When did you last see a biker on the phone, putting on her make-up, playing with the radio/sat-nav/air conditioning settings etc..
I used to argue with my parents about the safety of a motorbike when compared to a bicycle, and gave the same arguments as you mention, i.e. you can keep up with the traffic flow and don't have drivers doing crazy close passes, you are wearing more and better protective gear, and if the need arises you have the power available to get you out of certain types of trouble. The only problem being as before, when things do go wrong you will probably be going a touch faster than you would be on a cycle! My own golden rule on the motorbike is to never forget your vulnerability and try to keep a safety zone around you at all times. Keep the bike well maintained, and remember that everyone else on the road is out to get you (they're not, but some healthy paranoia is a good thing!).
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