Really there are multiple questions.

1. Fan comes on earlier than 150 degrees, is this okay?
-Will I see a short life on my ESC due to the fan constantly running?

2. If this is happening at such a low gearing ratio, will I be creating problems by gearing up?

3. Since I'm here asking questions, what should the motor temps be? I'm at 120 degrees right now. Again, with gearing up, will I be creating issues with over-temp?

Thanks.