Well, I m not too sure about the open-jaw part, but in Asiamiles ,it uses city instead of airport, so I presume Tokyo includes both HND & NRT.

Regarding to the transfer: If anyone who had redeem an Award ticket also help in answering this question.

Transfer:
2) Does the less than 24hr rule apply just like cash-paid ticket? Or do I have to take the next available flight?

Now there are 3 interpretation for this:

A) Stay at the connection city for less than 24 hrs
B) Must take on next available flight
C) Or in some cases, if the connection city has no flight to your next city within 24hrs, how does this work? Does it count as stopover or a transfer.