RE: First longish run
There's a kick-down 'of sorts', but it isn't related (or at least, not strongly related) to how the motor works or puts out power.
If you have set the speed limiter, then pushing the pedal to the metal bypasses the speed limiter. I think this is the main function of any 'switch' actuation you can feel at the bottom of the pedal travel.
In fact, you can dial up the full 75-ish kW that it indicates can be delivered with less than full pedal movement at certain speeds. Maybe it allows you a little more than the rated 70 kW if you do put the pedal full down, just as a short-burst thing.
You can actually lose traction at 30mph if you nail the pedal, because it puts out its full torque up to around that speed. It is limited on torque to 30-ish, and on power above that. The traction control is very good at keeping that torque under control, though, and I have never been daft enough to turn it off (it is a Very Bad Thing not to have anti-skid on in an EV because the tyres can spin up to truly excessive speeds very quickly in a manner that ICE doesn't (because in an ICE the power drops off in a low gear and with increasing engine speeds, so it reaches a limiting speed and torque defined by the gear (usually a low one), whereas for an EV it is essentially able to spin a slipping tyre straight up to its maximum speed! If the max speed of the Fluence is 84 mph, then if one tyre remains in grip on the road and the other spins up, that slipping tyre could hit over 100 mph while slipping and spinning, destroying the tyre very quickly).
Most EVs actually rate momentary power differently to continuous power. The 70kW continuous rating of the Fluence is pretty typical for all EVs, but some allow momentary excursions of power to much higher levels. Don't necessarily believe that the EV defined power is equivalent to another. The Spark EV is advertised as 95 kW and delivers an impressive acceleration for that, but its continuous rated power is 56 kW. I don't know if the Fluence's 70kW is continuous or peak, so you're not necessarily comparing apples or oranges.