How do reinforcements work?

As far as bringing on reinforcements, the whole thing is incredibly vague in the rules.

1) When in a player's turn are reinforcements brought on? Beginning? End? Whenever you feel like it?
2) Where do reinforcements appear? The rule says 'on the edge'; is that just on, or just off the board?
3) Can reinforcements be given commands the turn they appear? If they appear just off the board, then you have to be able to give them commands the turn they arrive, and arguably those would have to be 'free' movement commands. (If they weren't free, then what would you do if you didn't have enough commands for all of them?)
4) Can you voluntarily keep some or all of your reinforcements off board?
5) If you can, do they just build up so you can bring them all (or all you have commands for) on at once?

Okay, we found the answers to these today.