10. NAND is faster than SD, but smaller. By using SD, you are locked to having an SD card always present in the Pandora, and you can't unmount it to copy stuff onto it, meaning you'd need a second large SD card if you wanted to get movies or music or whatever off your computer. However, you don't have to worry about screwing things up with an SD card: install stuff, tweak stuff, do whatever to make your Pandora YOUR Pandora, and if you make a mistake and the whole thing goes wrong, just pop out the card and you can fall back to default configurations instantly.
13. Very, very, very gently tighten the screws if they concern you. If there's any resistance, stop.
14. You want
OVR files
15. Yes, if your Pandora is online and the router can forward ports to it.