Nice build!
A friend of mine buried all the plastic pipes in concrete and he still doesn't have a boiler for the in ground heating so he deviced something to pump hot water through the lines and checked with laser temp gun to locate the buried pipes so he can drill the concrete for anchor bolts for the two post lift without hitting the lines.
I built a similar shop, 30x50x12, and really think you are going to like it. YOUR SMARTESTEST MOVE <BY FAR> is the radiant heat. I am on my 3rd mild winter in mine with forced hot air, and regret not putting the water in the floor all the time! To the point one of these years I may pull my floor out and fix my wrong. Very wise, very wise! Welcome to the 30x50 club!