After looking through the complete thread I'll throw in my two pennies
I LIKE your first plan on two doors and that you thinned out the plans...but after that you took more tracks again so it looks a bit overcrowded to me.
I want to recommend you a nice book written by Marty McGuirk "N Scale Railroading (Getting started in the hobby)", Model Railroader Books $19.95.
My son and I read the book several times and also built a layout in our basement just like your 2nd trackplan - on two doors looking like an L with an extra door standing around for future extension....
Tim