My new ST-RR

I had an E-Revo (gorillamax) that collected dust on the shelf.
A friend of mine wanted to go from nitro to electric so he offer me his keyosho ST-RR kit for my ERevo roller.
I made the switch since the E-revo is more of a busher and I mainly driving on the track.
I already have Brushless Xray XT-8 and the ST-RR will be my backup on the track.

For the conversion process I used the Hexcrews conversion kit. The kit is very good and bolt directly into the ST-RR Chassis w/o any modification.
I'm using MMM ESC and KB36 1900KV motor from hobby king.
The results are very good, see below link. The only issue is the motor, It got too hot - 180F because of a broken fan.

I do have two questions for you guys:
1. I ordered the MEDUSA 60-1800KV motor from RCM to be use on my buggy.
Do you think that this motor will be better on the SR-RR and will accumulate less heat then the cheap motor from Hobbyking. It might be to small.
2. Other drivers on the track told me that the ST-RR kit is going to eat my Diff's for breakfast. Is it true? Any way to avoid it like using low gearing.

Here is the test drive on the Track:
http://www.youtube.com/watch?v=tNcf3WMTDsg