Have a Sound Value HO Scale S4 and was wondering if there is a CV value that allows the unit to power on with the sound off?

I am considering purchasing a Light Mountain in Union Pacific livery. 

I have been researching on the internet and notice that all of the pictures I can find show the engine with a short Vanderbilt Tender.

So, my question is:  Is the coal tender that Bachmann ships on this model, the correct one when the LM was initally sold to UP?

Thanks

I have a couple of questions about the reversing trolley set - can't seem to find the information I am looking for.

It appears that the time delay and reversing is built into the trolley itself and is not a function of the power pack or bumpers.  We think that when the trolley "hits" a bumper - the direction change is a mechanical vs. electronic change. Is this true.

If the above is true, can additional bumpers be purchased.

Also, can standard flex track be used?  We have a couple of tight spots that require 8" radius.

Also the power pack powers the trolley like a standard power pack - nothing fancy. We plan on using it, just want to make sure there is nothing special here.