Personally ,I would lose the turntable,put in a Wye for turning trains and use that entire area for a yard with some hidden staging tracks tucked behind a backdrop.(this will give you the (attached to the rest of the world feel and operability of other road names for interchange)
As it is now your longest classification track is about 5-6 40' lengths.
Now this is my opinion based on how i like to operate and how most operations oriented layouts are set up.Your idea's of how you want your rr to operate may differ.
A yard is not for storing trains or cars.It is for making up trains and getting them moving making money.
A yard that is 40% full is workable, a yard that is 60% full makes working it a nightmare.I hope this gives you some food for thought.
If the yard doesnt work right,it will effect the entire railroad.This is no time to be in a hurry.If you get the yard right for what you want your RR to do,operating it will be alot of fun.If its not right, you will tear your hair out and want to tear it out and redo it.
An extra few days now in planning how you will operate so that you can lay out your yard properly may save you alot of time later
It would be nice to have at least a couple tracks that would hold full trains(size is of course up to you but i would think a 12 car minimum would be good to shoot for

Some hints
Think in order of priority-mainline,Arrival/departure1 track minimum 2 is nice,Drill track long lead preferable so that it can hold an entire train to be set out on the ready(or a/d) track,interchange through freight classification tracks and local freight classification tracks.
Hidden staging of at least 1 eastbound and 1 westbound prestaged train(more is better but 2 is enough to add alot of interest to operations and keep your yard people busy switching)
Add to this LCL (with freight warehouse(possibly as a flat with loading dock)and team track or tracks .If you have additional room,follow this with any service tracks you have room for.