That demo is way more complicated than it need be.
The cab roof on Thomas is snap fit as seen in the pics,
press in on the front of the cab, and it will release.
the circuit board is screwed to the underside of the cab roof, remove it,
and you now have 4 wires, two from the wheel pickups,
connect red/black decoder wires,
and two for the motor, orange/grey decoder wires.
With the four connections made, address/test on program track,
tuck the decoder/wires back into cab, reinstall roof, and play!

with the loco on the track right in front of you, set the direction switch to the left,
if the loco moves to the right, anti-clockwise, reverse the wires, if the lloco moves to the left, clockwise, you're good to go.

get a hosting account (photobucket, flicker,...) they're free.
upload pocs there, a copy img link into your posts here.

You might also want to look at Glacier gravel.
link is to N scale version because the pic is better
http://www.walthers.com/exec/productinfo/933-3241
same style structure with different layout.
you could even bash the two together to better fit your needs.

think dirty, dirty, dirty.

This is about the only Hudson I'd be interested in.

the 3401 is setup for the 90' turntable, while the 2900 will work with thw new 130' table.

Base Zephyr throttle
F0, F1 - F8
But you access the higher functions by plugging in a handheld throttle.
UT4 and DT400 will give FO, F1- F12
DT402 F0, F1- F28
Loco buffer and Decoder Pro interface throttle F0, F1- F28
Adding the extra throttle also allows you to actively control more locos at once,
1 extra with UT4, and 2 extra with DT40X.

there is a screw in the bottom near the front truck
http://www.bachmanntrains.com/home-usa/dwg/dwgs/H114X-IS001.PDF

my 30" sections were one piece, the plastic part is three 10" pieces glues together, but the rails are one solid piece ( no joints).
The track is easily enough cut to length, but I agree that Bachmann needs a larger variety of section sizes.

make sure the black packing foam has been removed from above the trucks, also ckeck track and wheel gauge.

Standard protype heavyweight and streamline passenger cars are 85' long, with specialized cars like some baggage, rpo (60', 72'), and cafe/diners (70', 72') being shorter, but not always.
A few of the eastern railroads, operated shorter 60' coaches over some routes, and there were also super long articulated cars out west, but the standard off the shelf 20th century passenger car clocked in at 85'.
Both the Athearn, and Con-Cor make Streamline cars that are 72' scale feet long, except the Athearn RPO which is shorter (60') and represent shortened versions of full size 85' cars.
Add-on light kits can be added to either brand, and properly installed have no effect on radius handling ability.
Full length cars, really need 30" or more radus curves to look right operating.
I know you want a long string of stainless steel beauties serving your local depot, we all do, but if you keep your train short, say 3-4 of the 72 footers, pulled by a single F7 or A-B set, it will look better and more in scale with your tight curves.
When it comes to passenger cars, remember "Broader is Better"  

A soft lint free cloth, and some warm water with a bit of dishsoap.

It's not the radius of the curves that cause the PA problems, at least not the radius size of the track, that is...
The PA's problem envolves the vertical curves, (the dips and humps of the railhead on either one or both of the rails) because the PA truck does not allow for much vertical movement of the axles.
The truck can teeter-totter over humps, and if the track is uneven enough, the axle at one end is lifted far enough over the rail for the flange to clear, sometimes it comes back down in line, and some times it doesn't.
Removing the center axle, (the fulcrum of the teeter-totter) acts as a
band-ade, allowing  them to operate over ruff trackwork.
I too, use the PA as a benchmark gauge when laying new track, with it moving slowly, anyplace I can see the end wheels lifting, I will shim and level the rail, both rails, if needed, until the PA operates flawlessly, and when all is well with th PA, anything will perform well. 
This seems to not be an Athearn only, but a PA issue,  Proto, and the Kato N scale PA can have the same problem.

The motor capacitors can interfere with the BEMF on some decoders, removing them will improve motor control, and with the caps gone, the induction coils have no effect, and don't need to be bypasssed.