Not hard. Mute the second, third, etc engines in consist
Easy and easy to undo

Set both engines to the same address.  Many people do this.  Its easy and works fine

Baltimore & Ohio 2-8-8-4 "Yellowstone" Locomotives did run east of the Mississippi.

Miniatur Wunderland is extremely large model RR in Hamburg Germany.  They have set up truck and car movement. 
Do not remember what all it uses but vehicles move very realistic.  MR had article a long time ago on the train and road traffic.  Didnt look through all the stuff online about the setup there seems to be alot online about the RR

When the diamonds in Rochelle are replaced they are built next to the ones in service then replaced on the big day.  Not a lot of extra room 

4014 was at Global III Sunday. Was a static display from 9 till 3.  According to a UP press person
just over 60,000 came out to see her. 

For those in norther Il The UP 4014 will be at the Rochelle train part on Sept 8  Not sure what time
As of right now it is not just a run by.

Just got back from the Mad City Train Show.  Was crowded as usual, lots of young 20-30 people buying lots of stuff.  Was interesting to watch and listen. One layout had an Silver Streak train set including the E5 on the front. First one I've seen in the wild. Stopped and took some pictures from lots of angles. Had several younger people stop and ask questions and discuss the SS and engine, then got a discussion going with one of the people that was running the layout. Everything from track laying to the newest DCC stuff.  Was fun to listen to. Lots of ideas and good stuff. 

Most modern freight cars, except well cars, have 36 inch wheel.

If its the one in the middle of the car body,  its supposed to be open

Soundtraxx has the list on their website   https://www.soundtraxx.com/factory/images/bachmann/pdf/bachmann_ho_440_sv.pdf.  Dont know how to make it live.

The DH123 is an old decoder.  No longer produced.  The decoder manual states it does run analog, but will take a lot of volts to get moving.  Was not put in Bachmann locomotives as a stock decoder.  Bachmann used a modified Lenz decoder and a modified Soundtraxx decoder.  Some Spectrum steam came with full Soundtraxx.

F8 mutes and unmutes the sound on a lot of sound decoders.  Dont think unmute is a word but oh well.

Clean the tracks also. Is always helps.

How bout a O5A 4-8-4 for the Cb&Q?