To answer #1: The status LED blinks in that manner to signal that the unit is up and running. The two short blinks and pause are the normal operation.
#2: This is the normal state. Usually when the unit is rebooting both the status and LS lights go solid (lit). If they stay stuck this way or stay unlit then there is a problem.
#3: The LS LED is for Cellular. If the LS is not lit, either there is no Cellular radio or Cellular is not enabled.
#4: The only time either the status or LS LEDs will not have the behaviors described in #1 and #3 is if there is something wrong or, in the case of the LS, it will not be lit if there is no Cellular modem or Cellular is not enabled on the device.
Hope that helps,
Jeff