Re: Whats the deal with stick size?
I think a good place to start is get a standard sized pair of sticks, I like to start with a 5A, and play them a bit then make a not of how they feel. Do they feel to thin? Too light? Too heavy? Go to the manufacturer's website and look up the length and thickness and then try another pair that you think will be more to your liking. Eventually you'll find what size of stick you really like.
For me the Vic Firth 5A is a good meter. 16" length and .565" Diameter. Based on that I can get a good idea how a new stick will feel in my hands. Recently wanted to make the switch to a thicker stick so I play the harder accents with less effort. For practice I use a Vic Firth 8DN, the nylon tip is more durable and the lighter diameter allows me to play lighter.
The great think about sticks is that a new pair is pretty cheap, get a couple of pairs on payday and see how they feel.
Classy grip all day cause I'm just fancy like that.