Your gearing is about right, but it does depend on the size of the track u are using. If your on a track with a long straight and sweeping corners then you need to go up in gearing. If its a realy big track then go for 25/55. If however your track is on the smaler size go for 22/55.
Now since i gather that you are a beginner (no offence) i would go for the lower gearing anyway. The idea behind this is that you still make a lot of mistakes wich slow your car down. This means that you need to accelerate more then the "better" drivers among us, thus your motor needs to do more work.
Now if a motor is "hot" doesn't always mean that there is something wrong. Current day stocks are made to be used with the newer high cappacity packs so ampdraw is no longer an issue. With higher ampdraws however more heat is generated thus making your motor hot.