I am not sure about the Christmas Tree trail, but yes you can select certain shows/events that you want to attend as well as rides you want to hit. There is also a place to input your 3 fastpasses, any dining plans and breaks you want to take. You also enter the times you will be in the park, and how fast/slow you will be walking or the pace you want to keep up. You can choose to minimize wait times, or minimize walking. Once all those variables are in, TP will generate an "optimized" plan of attack for you.
I did a LOT of playing around with touring plans in the system on our last big family trip - I didn't end up using them once we got there, but it gave me a really good sense of how to approach our days, where things were located (how far apart things were) and good times to hit certain attractions. There are definitely some who use it as a strict itinerary too, for me it became a learning tool that allowed me to "wing it" a bit more once we were actually there