Hawke,
Fully explained and a great way to go I think. I have just been reading your thread from the start again and was wondering if you had done any more thinking on your "wiring" for the layout, not the least whether or not to use "Power Districts"?
I don't know how accurate this will be but I wouldn't worry too much about having "power districts" (per se), especially if you are not "electrically conversant". I would think that just having feeders every 3' would provide you with the wiring requirements for constant power around the layout as well as simplify your wiring work.
The idea of having "power districts" is to narrow down where any problem that arises maybe BUT, it is also to help with automation of the layout for signalling etc. If you are going to be the only one, or the main one, operating the layout, then I doubt you will need "power districts" as such as you will know what trains are running where and how. The argument for having power districts for identifying where a "fault" maybe is also questionable in my opinion. If you simply install feeders every 3' (give or take) and a section of your track work looses power (for some reason) you will know that it is probably due to a faulty feeder, and that can be only one of two - one of the feeders either side of where the failure has occurred.
All I am suggesting is that if you are like me and not confident, or proficient, when it comes to wiring, the less wiring you have to do the better.
With regards the question of whether or not to use a booster, I would say that it isn't needed especially if you have an NCE Power Pro 5 system. That "should" run 5 engines (with sound and lighting) without too many (if any) problems. Again, if you will be the only or main person running the layout then I can't see you running more than 5 trains at once, if you do, you are certainly a much braver man that I gunga din
The reason I am bringing this up is because you are getting to the stage where you should be thinking about your wiring, where it will go and how much of it you will need.
Anyway, as said, everything is looking great and am looking forward to seeing the start of the track work build.