You could also just use a couple of big conduit clamps on a regular bottle cage. Easy find in the electrical section of the hardware store.
Did you check the tire measurement in your controller? Mine is set for 26", which is the size of my tires. The odometer on the controller matches fairly well to the RideWithGPS app I use on my smartphone.
That wheel has to be trued. Lose spokes, wobble, frame/brake rubbing means the wheel has to be trued on a wheel truing stand. There are special tools for wheel truing and since your bike is under warranty, it should be free of charge. Riding a bike with an out of true wheel can cause you to break spokes and the heavy hub will make the situation worse. Not trying to scare you, it's just something that should be attended to.
Aha! That's why you got 35mi with 39% left! So maybe 5 to 7 of those miles are using no assist. I haven't been able to ride the bike more than 1/2 mi at most without assist, unless I'm on a downward slope, then I do turn off all assist. I believe my total range (using a combo of assist modes, all the way up to Sport and occasionally Boost) is a maximum of about 30mi. at which point the battery turns off completely, with no flashing of that last bar to warn me.I started the trip mostly unpowered with just using the throttle for the hills and to get across intersections quickly.
I would have a dealer look at your bike and ensure the torque sensor is properly adjusted. Having to work hard to engage the motor is a good indication that the torque sensor is possibly out of adjustment. The opposite condition of the bike running on when you stop pedaling for more than a second or two is the opposite condition and should be looked at as well.After riding it awhile longer, I think it's not a problem with my torque sensor. It's a problem with my expectations and riding style. You use the gears a little different with an electric bike, I think, than a regular bike. And that's what was causing the issue. When I was moving pretty fast on a high gear, I was annoyed that I had to pedal pretty hard to get the motor to kick on and match my pedaling. But if I downshift, the motor will come on with less pedaling effort. So, it's a matter of just getting used to how it works.
So, upon further reflection, I don't think there's anything wrong with my torque sensor.