Composition Render Getting Stuck

Question

I'm having trouble accomplishing a full resolution render in AE.  Originally I tried exporting through AME, and even on low settings it was telling me to expect at least 180 hours to render.  Within AE, whether its H.264 or PNG, if I have the output setting on full resolution I never make it very far past 45-48 seconds in the export before it becomes bogged down and slows almost to a halt.  Several times now I've let it run up to 8 hours long and haven't seen anything beyond 48 seconds rendered of my 4 minute project.  Often it'll cruise through the first 30 seconds at a good speed, but not much beyond that.
Within AE I'm able to knock it down to 1/4 resolution and get an MPEG2 to finish exporting in under an hour.  But obviously 1/4 resolution isn't going to yield me the professional product I want.  The project is just under 4 minutes long and I'm trying to make a high quality render for youtube.
My source media is:
1920x1080 (1.0), 24 fps, Progressive
48000 Hz, Stereo
My export settings that I want are pretty much the youtube HD preset:
NTSC 1280x720, 24 fps, Progressive
AAC, 128 kbps, 48 kHz, Stereo
VBR, 2 Pass, Target 8.00, Max 9.00 (profile High, level 4.1)
(I've also tried CBR @ .6 and that still clunks out past 30 seconds)
Hardware:
Intel Core2 6600 @ 2.4GHz
4GHz RAM
NVIDIA GeForce GTX 460 @ 2784 MB
Effects used:
This is my best guess at the hangup.  I have 155 AE elements.  Those 155 break down into:
69 motion trackers
2 solid layers (a slight color burn and slight vignette)
1 adjustment layer with 3 effects
2 sequences imported through the Premiere dynamic link including the motion tracking, a mask, 3 effects (including keylight, a simple choker and a simple wire removal), and a single audio track
77 jpgs (each with 1 camera blur effect)
4 short mp4 video tracks each between 3-3.2 MB

Answer 1

I stopped the jpeg sequence rendering.  Turned out like all of the others.  Ran for over 16 hours and only got 53 seconds into the composition.
Here's some screen shots.  The first is just a basic breakdown - the null objects with the tracking info continue all the way up to 1.  The jpgs/mp4 clips continue all of the way down to the bottom.  The middle is two dynamically linked sequences from premiere pro 5.5.  There's a solid yellow color burn above it at 8% opacity, an adjustment layer with curves, unsharp mask, and noise HLS, and a black solid vignette at 5% opacity.
This shot highlights the biggest JPG and mp4 transform details.
This last one highlights how I approached the tracking information.  Each shot had its own tracker.  A jpg is loaded and parented to the null object with the appropriate tracking information.  Highlighted is 75 (IMG_2087.jpg) being parented to 69 (Tracking).
As for the jpg and mp4 dimensions... looking them up now.
The mp4's are 320 x 240 and scaled sometimes up to near 1000%
The smaller pictures (IMG_2087-92) are at 3648 x 2736 and the big one I use for any shot with a big pan (bigcenter) is 7608 x 2736.  My composition settings are 1920 x 1080.  Sounds like a bad match!  And I've got 77 of these!