it's not unusual for corporate pilots to start #2 engine while passengers are walking up and boarding the aircraft. After the copilot gets everyone one on board and closes the door, #1 engine is started. Things work differently in the GA/corporate aviation world than they do the airlines.
As a corporate pilot, I'm the flight planner, dispatcher, ground services coordinator, fueling supervisor, de-icing supervisor, baggage loader, catering manager, ground transportation manager, crew accommodations/hotel manager, and lavatory servicing manager (i.e., I sometimes have to dump the honeypot). I've been a corporate pilot since 1988 and love every minute of it. That's why I really like HotStart's CL650!
Rich Boll