I am going out limb here so correct me if I am wrong Brian but the way I see it if you are running the same motor and ESC and the difference is gearing and batteries then no your run time will not be similar. Batteries are all made the same. The number of cells matters but a 2 cell vs a 3 cell 3500 mah battery will last the same amount of time. The difference will be in the voltage which can change your handling factor. ie jumps, cornering...
With this being said then:
1: no it wont. You changed the gearing factor which took away the voltage advantage you gained with the 3 cell. But it should run cooler. (I think)
2: No. Same as above.
Hope this makes since. I have been up for 38 hours so far.
