I'm currently in the process of booking my first DONE4. I'm planning on ticketing with AA to save on the fuel fines but my TA can only plate to AA if I'm on an eticket with 16 segments or less. I've planned the intinerary at 20 segments as follows:

MEL-HKGx-JFK-LAX-YUL-DFW-YUL-MIA-LHR-HEL-LHR-MCT-LHR-HKG-DPS-NRT-PEK-SYD-PER-DRWx-BNE.

My TA has done a quote on a paper tickets with QF but they want $1967 in taxes with about $1000 in fuel fines so I'm definitely going to go with AA.

So my questions are:

1. If I ticket with AA on 16 segments pre- 1 June (by dropping LHR-HEL-LHR-MCT-LHR, can I reissue once I've flown MEL-HKG-JFK-LAX-YUL in October and add back in the Europe sectors? (so I'm still 16 sectors on a eticket)

2. Do the pre 1 June 08 rules apply if my flights are ticketed in May (ie. 20 sectors permitted) but I reissue in October? (16 sectors permitted)

3. Do I pay the taxes & fuel surcharges on LHR-HEL-LHR-MCT-LHR when I reissue in October at AA fuel surcharge prices or is the whole itinerary then recalculated for taxes?

I figure the USD$125 reissue fee is much better than the extra $600-800 fuel fines I'd pay with Qantas.

I cannot answer any of your questions, but it struck me that your itinerary doesn't appear to comply with the rule about transiting Asia twice:

I think I should be right because MEL-HKG-JFK is the transit without stopover and then I have the LHR-HKG which is my second Asia arrival and does have stopovers.

I have used x to indicate transfer but maybe this isn't the notation I'm supposed to use???

The problem is that the 'transit without stopover' HAS to be between the Southwest Pacific and Europe, and your transit without stopover is between the Southwest Pacific and North America

0. pandaperth is correct and, yes, the x notation for connections is the right one.
1. Yes.
2. Yes.
3. Taxes & surcharges are recalculated on all segments yet to be flown.

Be aware that if your goal is to maximize QF status credits your North American flights are not ideal.

You will still get enough for QF Platinum but if you want to optimize make sure that you get a transcon flights which is not offered as three class and also try to to fly between the US and Canada as those flights usually are only offered as D class so you loose the advantage of booking into A.

Most likely every single North American segment in your itinerary will only give you D class and not A.

You also need to find a way around the double Asia entry problem. You can avoid this by doing your Asian segments first (before you go to the US) and then connecting from LHR directly back to Australia towards the end of your journey.

EDIT: I forgot, you are going to Uni in YUL. So you don't maximize SCs, you actually want to do something with your ticket. Maybe fly to something close to YUL within the US and buy a cheap ticket. Helps with lifetime status.