Questions about the Arduino Micro PCB I'm planning on integrating an Arduino Micro in the circuit of a small project of mine (USB gamepad). The whole thing will use USB for power and data transfer (between the board and the computer). Before I move on with prototyping, I need to clear up some questions I have about the Arduino Micro schematic (picture included for reference):


Since I'll be powering off of USB, I won't the 5 and 3.3 V regulators or the 5 V Selector (top-right in picture). Am I correct?
For the USB Micro header, does the schematic refer to any particular header (doesn't seem so to me), or will any generic one work? And what are the six pins on the right side (SH1/S1, SH2/S2, SH3/S3, SH4/S4, SH5/S5, SH6/S6)? What do they do? What are they used for? I found the pins on the left (VBUS, D-, D+, ID, GND) on generic USB Micro headers, but I did not find the pins on the right.
Out of curiosity, what do the asterisks in the schematic mean? You can see them all over; for example, look at the top-right of the MCU.
What do the circle and the smaller circle (with an X through it) towards the bottom-right mean?
The 5V regulator is only used when you are powering from external power (>5V). The 3.3V regulator is only used by things that you power from the 3.3V pin on the Micro.

So if you aren't using external power you don't need the 5V regulator. If you aren't using any 3.3V devices then you don't need the 3.3V regulator.

You can use any micro USB or even mini USB connector you like. If you ignore the "ID" pin you can even use an old-fashioned chunky USB B connector like on the Uno. 

The circles are fiducial markers and are special patterns on the board used for aligning a pick-and-place machine when manufacturing.