Hi Jaytee,
I had a similiar layout plan that was Dogbone or a folded Dogbone can give you a fair amont of operation with some diversity in running too. Of course what I'm talking about is having some differences in elevation where one line will curve around over the other to increase elevation to a secon level.
From what you show you may be limited by the over all diameter of the end loop/s you plan on having. My layout room width is 10' wide and with a loop table width of even just 46" leaves me little room in a 10 wide space. Now you have 11 you said but your probably going to want curves much bigger than my 20" radius plus a little for edge scenery so lets say you have 24" radius which is 48" diameter but because that is the measurement across the loop from the outer rail on the far side to the inner rail on the near you still need to ad about an inch to figure in your tie width and as you don't want your tracks right on the edge of the layout you'll need to ad at least 1 more inch on each edge so that's 50' 's overall per loop or a little over 4' or 8' total giving you three feet of center space with a back depth of 30". Now what your also going to have to contend with is how your going to curve your tracks around from one side to the other across the 3' middle section, if you want continueous running, as that's nowhere near big enough to allow the same 48' radius to fit in. You might be able loop the track under itself and get them to inter connect? If you have a track design program see what you can come up with but a Point to point type of track plan with just one loop, might work out best unless you can have tighter radiuses and that will require shorter equipment than you might want to run?
To answer your question as far as reach over it's not quit as simple as it sounds. Let me give you and example using the layout I'm constructing.
The first thing you need to determine is the height you going to have your layout at, usually about waist height or above is pretty normal, mine is 45-1/2" and as a general rule a 30" deepth is what is considered an acceptable reach over. Mine is a 30" table width with the execption of the end loops, my basic design [__] but because my track has an elevation difference of 9" from the front to the rear upper line I required a substantial step stool with with a handle I can hang on to so as to be able to comfortable reach over to the upper tracks as well as working with back drop scenery which I'm planning on putting in after I get a better idea of how the trackage and scenery will tie together.
So therein lies the question? Are you planing on having your tracks basically on one level or maybe minor elevation changes in which case you probably can get away with a simple reach over as long as your table work isn't too high for your height. But also consider at what elevation you want to view your trains and scenery so it looks more realistic without having to stoop much.
If your planning on doing something with some healthy elevation changes even a 30" depth can pose a bit of a challenge, as in my case.
Also a good step stool, I got mine from WM it was the Cosco brand and has two steps with the top being a nice platform to stand on for about $25.00, is invalueable when it comes to reaching into back corners which aren't accessable otherwise, I'm going to have 4 on my layout and needed something to make it simpier. Of course if you don't have much trackage in the hard to reach corners so much the better but you will still want to scenic them so you'll need to reach over at least a little bit.
Hope that helps a bit.