First, your video is showing that it's private so I can't view it. The motor rotation reversed? The only way that should happen is if you switched two motor wires (can't do that in sensored only sensorless), changed the motor rotation in the esc settings, or reversed the throttle channel on the transmitter.
Second, did you install the transmission years that were included in the Losi kit? I almost forgot about them and they do raise top speed which isn't always the best thing but in this case should be fine. Those Ofna/Hobao tires are actually shorter in diameter than the stock LST tires lowering top speed a bit. You shouldn't have a problem with 25/63, even with the stock LST tires and the Losi conversion kit gears installed in the trans the top speed should be low enough for the motor to handle.