Yeah, man. Thanks. I've got all that detailed out in the recipe linked in the OP, but the sausage thing I wasn't sure about. So thanks for confirming.
So, Ed, if I didn't want to make a besausaged "Lou" but a sausage/spinach DD only, you think I should assemble as if I were and just omit the sliced romas, cheddar, mushrooms? That's question #2 in my OP. It seems like a good method but maybe there is another way I should be assembling it?
Thanks.
Bonus points for "besausaged". We also would have accepted "sausage-inated".

Spinach mix under the mozz, sausage above the mozz, and if you're leaving out the sliced tomatoes, you can use the normal amount of "the usual tomatoes/sauce" instead of the scant amount they use on the Lou.
That would be the likely way with a spinach/sausage combo.
I haven't made a spinach deep dish in some time, but most of my tests had the spinach pre-wilted/sauteed with garlic, olive oil, and honey to balance out the bitter, cooled to room temp or refrigerated, then added on TOP of the mozz, but under the sauce.
There were a few times I tried fresh baby spinach on top of everything, but I wasn't very happy with the results.
Here's pics from a sausage, spinach, pepperoni deep dish I made in June of 2014 (I have a LOT of deep dish photos).
If I recall, I put raw baby spinach on top of the mozz, added a layer of pepperoni, stuck pieces of sausage on the pepperoni, then sauce, then more spinach.
It was a delicious mess, but I don't recommend this build. Way too much liquid.