Still some confusion between reservations and tickets I think. If you're going to make lots of changes then the best way to get the ticket done is to confirm the first segment (strictly up to the first international segment) and then make all the other segments open-date.

You can then get as many separate reservations as you like for the individual segments that you actually want. When you make the reservation you simply tell them the number of the ticket you are going to use. The ticket doesn't have to have that segment routing on it at this point - just tell them that you will reroute the ticket nearer the time when you have managed to lock down all the flights. I have done this multiple times (albeit always with paper tickets, which I very much prefer) and never had significant problems.

For example, I might initially ticket a DONE3 as CAI-xLHR-HKG-SFO-xLHR-CAI with only the first two segments dated because they were the only ones that I knew I actually wanted to fly. Then I would get separate reservations for the segments that I actually wanted to fly after HKG, getting the ticket number entered in the reservation. Generally I would book the segments directly with the airline flying them, so I would then end up with, say, a CX reservation for HKG-NRT-HKG-DPS-HKG-JFK, an AA reservation for JFK-DFW-ANC-DFW-ORD-SJU-LAX, and a BA reservation for LAX-xLHR-IST-LHR-CAI.

When I went to HKG to get the NRT flight I would simply go a couple of hours early and get them to do a single reissue of the ticket so that it now had the new routing:
HKG-NRT-HKG-DPS-HKG-JFK-DFW-xANC-DFW-ORD-SJU-LAX-xLHR-IST-LHR-CAI
but with all the segments open dated (just because it makes the job of the person doing the reissue hugely easier). I'd wait in The Wing while this was being done. An hour later the new ticket would arrive and I'd be good to go.

This has worked well for me many times.