Kevin,

Thank you so very much for taking the time to answer my questions in such detail.  Very much appreciated!

I've just ordered the Yellow Pine Mogul 2-6-0, and I am very new to G scale.  And very excited.

I have a small setup just for holidays, and I am running DC.

I see that the locomotive and tender include the chuff sounds, but what about a whistle/bells? 
Do I need to replace what's in there with a phoenix system?  If so, is this easy to do?
1 more, can I control the whistle with something manually, like a push button?

Ok, 1 more... Are there any options in G scale to control the locomotive and sounds with a mobile device, such as iPad?  I want to be the cool uncle this year, and have as much enjoyment possible with this beautiful train.

Thanks so much in advance.  I apologize if I missed a thread that has some of these answers already.