Risk. It is all about risk. Priorities should always be set depending on where the greatest risk exists. Cars/drivers are a significantly, SIGNIFICANTLY greater risk than bikes/cyclists. Fact.
Perception. Now that is a different thing all together. Very often people perceive cyclists as a risk and a nuisance. Unfortunately human perception isn't the best, especially when it comes to determining risk.
Education. That's the answer. Education of non-cyclists, i.e. what the real risks and benefits are, and education of cyclists, i.e. what the best road practices are.
Should it be necessary for cyclists to have taken a test? Actually I like the idea, but practically it would never work. So many people would flout it and it would be impractical to enforce. Should cyclists be encouraged to take courses/tests, absolutely.
However, the greatest benefit to all, would not be the introduction of tests and training for cyclists, but the introduction of a cycle 'proficiency' part to the driving test (for those medically able). Not only would drivers be more aware, but cycling standards would improve as well (how many of us cycle).
Anyway, thats my 3p worth.