I am hoping to convert the wheels on a Bridgestone MB-2 to quick release. I have done a bit of research and am thinking the best bet is to buy replacement axels with the cones, spacers etc. A couple of things I am wondering about, and would appreciate feedback on. For this I am presuming I will need to have a smaller axel than what I presently have, as I have been told quick release axel diameter is smaller than my solid axel.

1. How critical is the cone radius, or is it critical at all?
2. Will my freewheel, cassette (shimano 600) move over to a different size axel?
3. Anything else I should be concerned with?