I wouldn't touch the Surface in light of Windows 10's issues with privacy. (Not that iOS doesn't have some issues itself.)
Windows 8.1 is amazing on the Surface Pro. W10 is a major step back for me. It's also the perfect form factor for reading graphic novels, although it's easier holding an iPad Air for extended periods.
Your not the first one I have heard say that but the screenshots I've seen of Windows 10 makes me think it is still pretty usuable.
Well put Linux on it then. No one's forcing you to use Windows.
Using a Surface running Linux sounds like a proper definition of "hell."
When you're entire stack (phone, desktop, tv, etc.) is already Apple, this would make no sense at all.
More effective storage space? IIRC Surface is notorious for chewing up a huge chunk of the internal storage with the OS et al.
In fairness to Microsoft, they have been working on reducing the space Windows takes on the drive. IIRC, Windows 10 introduced some new features to combat this. Also, storage is expandable by its SD slot.