Unfortunately, these troubleshooting steps have not worked for me, and I'm not even running the NGX in here.
So far, here's what I've "attempted" to do:
1. Start at CYVR at gate 73
2. I load using the cessna, and then switch to the Aerosoft Airbus X Extended
3. I have a 50/50 chance of getting to pushback before I OOM.
After doing multiple tests, I would definitely say that going into spot view and looking around the aircraft will make it happen faster.
Now, after reading the original posts, I figured I could go ahead and lower some tweaks I had made earlier to try and resolve this.
However, to my surprise, when I opened my FSX.cfg, all these things were already set. LOD was 4.5, MaxTextureSize was already 1024.
I tried removing Vancouver+, which seemed to help. I managed to taxi to the runway before I OOM'd. I then tried turning on DX10.
DX10 helped immensely (or so I thought at the time), and I was able to get out of CYVR and enroute. Then, on approach into KLAS (also FSDT), I noticed that none of the terminals or ground textures were there. I noticed this on my downwind, and figured it just needed time to load. By the time I got turned around and onto final, nothing.
Made it all the way to the jetways (which oddly were there, floating in midair) without the rest of the airport loading. I promptly went in, disabled DX10 and restarted FSX. Loaded up at KLAS, and everything was back to normal.
So turning to DX10 made my night-time landing into KLAS not have buildings or ground textures. Weird. Very very weird.
As a test, I loaded up my NGX at CYVR. I pressed the battery button and it OOM'd. LOL.
Here are the addons I'm running in these tests:
-> FSDT CYVR
-> FSDT GSX
-> ORBX PNW
-> AS2012
-> UT2 running ~40% traffic load
That's it.
I had one other flight where I was able to get out of the terminal area without an OOM. I didn't use GSX features except for pushback, I didn't leave the cockpit to look around in spot plane mode. Ironically, the flight was from CYVR -> KLAX (FSDT, of course

) and I got my first ever OOM into KLAX.
I have every single FSDT scenery (except for LSGG/LSZH) and have never had a problem. Do my frames slow down a touch when I'm going into rush hour at KLAX or KJFK? Sure... but never an OOM or missing buildings, or anything else bizarre.
If I had to bet money, I'm thinking there is a problem in Couatl, and NOT CYVR.
Other things I've tried to remedy the problem:
-> Re-install GSX
-> Re-install standalone manager (twice)
-> Wiped my FSX.cfg and let it rebuild default
-> Cried
-> Prayed
Also, for reference, here are my system specs:
CPU: i7|2600K OC@4.4Ghz
RAM: 16Gb DDR3 @2000Mhz
Video: nVidia 560ti (No OC)
HDD: FSX is on dedicated 7200RPM SATA6b/s
To be clear: I'm not expecting a miracle fix, and I understand you are not psychic. If there are logs or any further info I can provide, I'm more than willing to help out.

I still love FSDT, and I think you guys are really pushing the boundaries of what's possible. With new frontiers, are unforseen landmines, and I'm more than willing to help clear them out with you.

Let me know.