Can I charge my MacBook with a phone charger? Can I use a phone USB-C charger (e.g. the from google) to charge my 2016 MacBook Pro? How about a USB-A charger with a USB A->C cable?

Physically it fits, but this answer says that it is not a good idea, without elaborating why.
The reason you can't do this is a matter of input. 

The 13" MBP has a 61W charger - a lot more than your typical phone charger brick. Check your phone brick and see how much of a difference there is. 

Your Macbook would probably not even accept the charge because it would be so low