Here’s my take on it.
Puppies need to walk, to be able to explore their environment. The best way to do this is tethered to you, rather than in a sling of some sort. Does your company frequently see dogs on the floors? If not, I don’t see why he can’t be on the floor.
Use the crate more than occasionally. If you cannot have him tethered to you, he should be crated. I would also consider picking up an xpen so he has a safe space to play outside of the crate from time to time.
Frankly, I like the idea of taking him in to work right away, especially if you’ll continue doing that when he’s an adult. If you don’t intend to continue taking him in when he’s an adult, I don’t think I’d do what you’re planning, simply because he’ll wonder why you’re suddenly leaving him home when he’s older.
Did the vet do a skin scrape?