Apologies for the delay, I didn't realize there were replies.
I've built it so that it should be motorizable with two Power Functions Large motors, and I have pieces in the front that can be taken out to make space for power functions lights. The tender should fit two small Power functions battery boxes, as well as one receiver. Because of the configuration of the motor and the length of the train, it would require a power function switch to reverse the direction of the front motor. It has enough space to be compatible with the Powered Up Large motor, but the cable would not reach, so it would require a third-party extension cable, probably best with a splitter that reverses the direction of the front motor.
Regarding point three: there is actually color accents with the stickers I included for my submission, but since I run Linux on my desktop, I didn't have access to the Parts Creator software that would have allowed me to show what the model would look like with stickers. The tender, cab, and smoke deflector would have red bars running along the edges, and the boiler would have gold stripes.
Thank you! I thought it was a good way to show how thin the smoke deflectors are in real life, since it's difficult to represent it with something thin using LEGO.
Thank you everyone for your positive comments! My model was approved for the contest, and will be moving on to the crowd vote phase.
