Just two comments about your trackplan. Since you have no way to reverse a train's direction after it leaves the engine area, why not create a wye by inserting a left hand switch (facing "north") into your longest straight track next to the wall, run a curve across the two tracks that lead into your engine area (may have to adjust tracks for crossings), and then join a "wye" switch which you plug in to your outside curve just after the crossover?
Second, consider starting your passing sidings with switches that start on your loop curves. This extends the length of your sidings without interfering with any other operations.
I have attached a SCARM file that used Ross track and switches to give you visual suggestions. Good luck and have fun.