If you have some time most of your questions are answered in this set of lectures about the subject from someone in the field https://www.youtube.com/watch?v=pC

If you have some time most of your questions are answered in this set of lectures about the subject from someone in the field https://www.youtube.com/watch?v=pCceO_D4AlY&list=PL22J3VaeABQApSdW8X71Ihe34eKN6XhCi&index=13&t=9m3s https://www.youtube.com/watch?v=pCceO_D4AlY&list=PL22J3VaeAB.... If you don't a lot of time then the 10-20 minutes or so from where I linked are also useful and answer a lot of the points you brought up.