Yes, the VXL will run a neu. Going off of Traxxas's 200a cont claim you could run up to a 1521 but their is no 1521 in the kv range that you would want seeing that you will be using 3s. For a good reliable setup I would go for a Neu 1509 1.5d. If you want somewhat of overkill go for the 1512 1d.
I dont think a 1509 is at all needed, or will run hot. I think you for sure will have drivetrain issues with the 1509 LOL. I personally would run a 1509, but the 1506 is more then enough!
The Medusa is a step above Feigao motors, but not quite as efficient and cool running as the Neu motor. You shouldn't have any problems with the Medusa in terms of heat though as long as you pick the right size and KV motor. They are much better than Feigao motors.