If you are stand still, your velocity will be 0. If you hit full throttle, then your max speed will be reached in a certain time. Acceleration.
Boost (single hold) will speed up the time between 0 to max speed. Boost increases your acceleration.
Strafe is just a vector on a straight line. Boost also affects that vector. Your speed on the HUD is the speed straight forward, not the vector speed.
While strafing and turning, your are actually making more G-forces then you would have if you are only turning. G-safe tries to keep you G-forces within safe limits by correcting you max vector speed. Boost overrides G-safe and accelerates to your max vector speed.
Afterburner (double tap) will raise your max speed so you can go beyond your maximum vector speed. I don't know if afterburner also increases your acceleration. Afterburner also overrides your G-safe.
Please feel free to correct me if I'm wrong :)
