I found that majority of Windows 8.1 optimizations will still apply to Windows 10 – as far as the backend is concerned, not much has changed between 8.1 and 10.
I do keep couple services alone, however:
1. Microsoft Account Sign-in Assistant: Required for Universal apps (or any Windows store apps) to function.
2. Windows Store Service: Same reason as 1.
3. AppX Deployment Service: Same reason as 1 and 2.
4. Windows Search: Required for Cortana or search bar to function (just be mindful of that IOPs though).
Given how much emphasis is given to those functions in Windows 10, I’d keep it enabled. Disabling them might drive your users away.