For working at Google you seem to know very little about them.
1. Data was sent even though location history was turned off. [1]
2. It is pretty well-known that SSIDs can be used by location services to increase location accuracy, especially where GPS coverage is low or noisy [2], or slow to connect.
3. Would be useful for location tracking again.
4. That seems like a bug that wouldn't really benefit Google at all.