John, you are doing well. However, just a caution...another one of those pesky things to consider...except this one is a monster that sleeps under your bed. If you can't reach a portion of the layout because buildings, trees, power poles, hills, or just a lot of terrain, are between you and what you need to fix (and you will need to fix stuff on your layout), it will be an endless source of frustration. Access and maintenance are two givens in the list of givens and druthers. You have to have a way to reach stuff. If you tracks are all within easy reach, you can have lots of stuff behind it that you won't need to touch.
I don't know if this means anything for your vision, but just keep that in mind...access and maintenance are huge for keeping the fun in a layout over months.