You should run a fan since you're running your whole pack out. I try to stay at 130-140 for longevity but 150 at the end of a run is ok.
And timing can absolutely add low and mid range punch/acceleration. Timing actually wont increase your top speed, if you are hitting the motors RPM max. If you aren't hitting that point the extra timing will make more power to get it to that point though.
Brushless motors are weird sometimes gearing them up (larger pinion/smaller spur) can make more mid range acceleration as it forces the motor to use more amps to push the car. If the esc and battery can provide it, it can actually be faster. Also if you're under geared and the motor is over revving it may run hotter than if it was geared where the motor wants to be.