Most of these changes would have had to have gotten started under Balmer. Nadella has only been at the helm for two years. If anything, Nadella has been doubling down on a plan Balmer put into motion.
Not quite true, Satya led cloud and enterprise org. before stepping into CEO. Many of the initiatives at Azure started with direct involvement from Satya. He also pushed for open Microsoft long before becoming a CEO, its just that now he is the CEO, he can make it happen.
Yes, Microsoft Patterns & Practices were there from 2002/3 onwards i remember patterns on app move from Unix to windows instead of linux and MS has Services for Unix posix 1.x compliant at that time so all basic linux tools (ls/sh/awk/sed etc) and api worked on WIndows 2003 with NFS and NIS compatibility