It seems[0] that the Android bought by Google was a camera OS with cloud storage. Not a phone, nor did it have apps. All that came from Google, and was being developed before the iPhone was announced.
If you read Battle of the Titans, you'll see Android was left to its own devices once acquired, so you could say it was a team that what would eventually build the Android we know, regardless of who bought it. Google contributed cash but didn't do anything Microsoft couldn't if they had acquired them.
Completely disagree. Google shared mobile search ad revenue with carriers and device makers using Android OS. Microsoft couldn't (as a matter of practicality) offer that advantage.
Fair enough, but do be careful of founder revisionist history. Independent research is usually better at digging up company origins than the "tales from the inside" that founders tout. (Though I'm not disputing the revenue split advantage)