>>1
It depends. Like any system, it will take several years for you to be a whiz, zipping around doing stuff.
Many people probably learned it the same way (like I did); by installing over and over and practicing all the time. You'll find new things you want to do and you'll figure them out.
Hardware support can be frustrating, but in general, it's as good as the coders can get with the limited information available.
While it's a simple answer,
>>2 is right. Just install it and play around. Break your machine. Reinstall.