If you're looking for ultimate control, disable the PAS and just use the throttle. You can pedal with as much or as little effort as you want, provide as much motor assist as you want.
Others have different opinions but I couldn't get used to the PAS on my BBS02. I like being able to get things rolling under pedal power, and once it's spinning hit the throttle and let the motor take over. If I really want to get off the line quick I put pressure on the pedal and simultaneously mash the throttle.
When I'm climbing a hill, I slack off the throttle and pedal as hard as I feel like. It feels much more natural than fiddling with PAS levels while I'm busy riding in traffic. It's nice to be able to pedal gently through a set of baffles without the threat of being suddenly "assisted". Shifting smoothly is second nature, no shift sensors or brake tapping or any of that, just back off the throttle and shift the same way I did before I had a motor. Shift complete, back on the throttle. Even shifting without the pedals, throttle only is pretty slick with some practice.
There are programming options for the PAS levels, fairly detailed settings for how fast the power ramps up and down when you start/stop pedaling, max crank speed/power for each level, and a bunch more settings. I fiddled with them for a while, but never was happy with the way it worked.
So I snipped the grey pedal sensor wire on the controller and never looked back.