Please comment on current 13.5'x9.5' layout

Is the bottom of the picture open where you can access the operating accessories area from that side?  You don't have it marked as a wall so I assume so.  

The big loop up to is good, lets you run your big engines and cars.  Also, no switches means you can run older trains that may have flange or gear interference issues with some brands of switch.  No ramps is good here, layout is too small for them IMHO.  I have a 15X13 G shaped layout and am adding an upper level loop but it will also be a single loop, no ramps.  They take up too much space before you even get to the challenges of ramps on corners and train length etc.  Lots of things to deal with when using ramps. Personally on the bottom, I would alter it such that the inner small loop either disappears or is a part of a second full inner loop.  Do that and maybe a siding or too can fit in that small loop area for your accessories.  Also if you will run passenger trains, you might be able to insert a passenger track or two on the left side of the lower loop(s) with a station there.  You could have a long enough straight for a 3-4 car passenger train and not block the main line loops.  Also depending on your design and wishes, you might be able to get yourself a little more lower level space by running part of the outer lower level loop under the top level loop.  You can do that as it if is an elevated line or cover the lower line for  short distance as a fill to upper line.  Lots of tricks you could consider. 

I don't know what brand track you're using, so I just used RealTrax to illustrate a different yard configuration with O31 switches. Starting the yard on the curve allows you to eliminate the "S" curves and have a smoother flow in/out of the yard as well as giving you a little more space for longer storage tracks.

BEACHHEAD2, yes the bottom part is fully accessible, so I've added some text there.  Thanks.

Dennis, comments are great.  I realize there is a lot of space under the top O72 loop.  I've readjusted now with a very long line down far left under upper O72 loop and pushed the bottom of the O64 loop underneath the bottom part of the O72 loop.  That let me put in a passenger line into the yard.  I could come down similarly fr0m right side for maybe 4 feet until I hit the bridge/lift up/swing out (don't know yet... another thread).  What to park there???  Could bring that line all the way down, under bridge, to make yet another bigger O64 loop but then I'll have three tracks close together on a bridge/lift up and that sounds like a disaster waiting to happen.

Anyhow here is the updated version.

Not sure if the Inglenook is right... wrong kind of switches I know but I have O22s.  Up at top there are 7 switches that'll all have to go remote.  Those switches could also be a disaster area so if anyone wants to comment there especially would be helpful.  Outer two loops will be Ross/Gargraves 3-rail, Ross switches except form just two old (but in great shape) Lionel O22 switches (straight portion) on top.  Everything else will get whatever track I have available. 

Better picture is attached.

Here's a better one with better sidings thanks to DOUBLEDAZ.  I also went ahead and added ability for trolley on far right under the outer O76 loop. Can take people from the city to the station at the yard.  Don't want to add any more track that I have to clean!