I had not thought about stubbing my plumbing out along an interior wall. That is good thinking. I will run some plumbing prior to the slab. I can stub it out on the wall between my wife's room and the shop.

My shop doorways will be 10' tall (that's as high as I can go, the trusses are already there) and 14' wide. I will build (2) 7x10 doors for each main doorway.

I have a few sheets of plate glass (4x6 I think) that I was thinking about casing out in a wall for some natural light. I still haven't made up my mind on that.

This is a true statement. Mine is 44 x 48 and I'm fixing to add on another 14 x 44 (stinking camper costing me money already). You can do a drain in the floor or another idea it to raise the slab where your closed finished area is going to be about an 1.5 " from the rest of the shop, that way when you wash down the floor you don't have to worry about it getting under the wall and into the finished room. I didn't do that on mine and I wish I had done that. There are a lot of other good suggestions on here as well in regards to plumbing and electrical.