Originally Posted by sony2012

I have some newbie questions for DONE4. I just learned that i booked DONE4 according to JAL website (otherwise I was not sure lol)
1. There is no total flown mile restrictions such 34K, is that correct? The reason I am asking this is because oneworld web kept giving me this error when booking
Correct. There is no mileage restriction on a DONE ticket. The continual display of the error is a known bug in the booking tool.

2. The total of 16 segments including the free transfers. So if I book a ticket to London and start in MAD, LON-MAD segment counts as one segment even though the flight is not included? This might be the reason why I kept getting an error when I tried to add segments under 34K miles at the time of booking....
Sorry, I don't understand what you're saying here.

3. How about landing in LGA and departing from JFK. Does the transfer between LGA and JFK count as a free trasnfer segment?
As ​​​ironmanjt said, it counts as a surface segment, and is one of the 16 allowed segments on the ticket.

4. Within each continents, there is a limit of number of segments I can fly. 4 segments in Asia. Does it include the free transfer? So if booked two flights with two segments each: JFK-HND-BKK-HKG and HND-HKG-LON, how many segments in asia am I using??? 3 or 4 including the free transfer?
Surface segments are not flight segments and so do not count towards the maximum number of flight segments allowed in a continent.
You are using three flight segments in Asia: HND-BKK-HKG and HND-HKG.
(And you have a surface segment HKG-HND? This could be a flown segment.)