It really depends on your height. If your legs are longer, you should use that to your advantage and use the leverage of a longer crank. If you use a longer crank and don't have long legs, you can feel like you're riding a hear or two higher than you actually are, so make sure you don't get cranks that are too long!
Usually not. It'll be fast at the start, but a small crank will limit top speed unless you can turn the pedals really fast.
A crank (or a crankset) is the thing that sits in the middle of the bicycle, has the chain on it and have the pedals attached to it.
No, only the one that was made for it.
You measure it. A ruler and a caliper are useful.
Yes you can, but take it to a bike shop or someone who knows what they are doing
Because they have small wheels. To get any speed out of a BMX they have to have small sprockets. It's all about ratios.
It depends if you have a 3 piece crank, spokes, brakes.
By crank do you mean sproket? The smallest iv seen is a 22t but there may be smaller, or do you mean 3pc cranks?
Haros are the best and damondbacks with small cogs are the best BMX in the world.
BMX videos are quite popular and can be found on YouTube in large numbers as well as on many websites dedicated to BMX. These include BMX TransWorld, Bikes Belong and BMX Mania.
The only thing on a BMX regularly called a spindle would be the crank axle. Although I suppose one could use spindle for the pedals and the wheel axles as well.
I think a freestyle bmx should be made out of steel but I've heard bmx's are made out of chromoly or alluminion, i hope that's just for racing