That plan is a lot of trackage!!!
I think anyone building a new O Scale/ O Gauge layout needs to choose:
1. Model railroad?? So you have to realize what you are creating is a "caricature" of real railroading. So you need to have abundant scenery to even simulate "real" train environments. In 1:48 and in 16' X 10' you are not going to simulate a full scale railroad in actual scale. So you do the best you can, using visual tricks to hide the reality that you are stuck with. Just build it and enjoy it, but IF you want to do the whole hobby including scenery and buildings, then you can't have a lot of trackage.
OR
2. Toy Train layout?? In this case you are recreating a "train set", like you might have loved as a kid. So a lot of trackage with out of scale accessories, is fine. But that's fun too- and you should do it if you like it.
I just think to try to do BOTH is fruitless- I don't see that much trackage looking like a real railroad.
