OK Robert
First the red light is not a problem. I wish manfacturers would do as the long established e-bike makers like Heinzman and Giant do, stick the meter where it can't be seen when riding so it doesn't worry people. You see, there is no way that a battery's content can truly be measured by a meter, the only measure we have for the content is watt/hours, so it can only be measured by using up the content over time. The meters we have just measure the small voltage drop as the battery content is used up, and that's roughly good enough a measure when the bike is standing still. Trouble is, when on the move and we open the throttle wide, the current drain into the motor also drops the voltage, so that's recorded on the meter as well, nothing to do with the battery content. The equivalent on a car is when we plug the starter with headlights on, the headlights dim due to the voltage drop the motor causes. When the weather is cold, that drops the battery voltage as well, so you can see how pointless these meters really are.
The Li-ion batteries are nominally 37 volt, the NiMh are 36 volt. If I put the NiMh that I also have into the Torq fully charged, I can go onto the hill outside my home and get the red light on immediately, simply because it's started with a lower voltage point, nothing to do with what's in the battery. So my advice on that is, forget the meter when on the move, better still, put a strip of black PVC insulating tape over the LEDs, and just check the level when standing still. Find out your range, starting with an assumption of around 13 miles and gradually take a bit more until you find the cut out point near to home.
The shudder is probably just head bearing adjustment, this beds in very quickly and often loosens in the first few miles. Any cycle dealer could fix this easily.
However, none of this alters the fact that you have the wrong bike I'm afraid. The Torq is no hill climber, the motor is far too high geared in the 28" wheel for that. It's the equivalent of having a car locked into top gear all the time, fine for gentle main road slopes, but brought to a stall on steeper slopes. Indeed, the manual with the bike says up to 10% slopes, so anything over 1 in 10 is outside it's specification. I also have a Quando which uses the same motor in a 20" wheel, and that can pull away without pedalling up a 12% (1 in 8) hill, so you can see it's just the wheel size that's the problem. The eZee Sprint with the 7 speed hub would have been a much better choice since it's lower motor gearing makes it a better climber despite it's slightly lower power motor (500 watts against 570 watts). As you've done such a low mileage, I suggest you try to negotiate a change of model with 50cycles as the only solution that will give some satisfaction.
P.S. You're right about the derailleur ratios, the 58" low really being a middle gear. From a design point of view it's right of course, since the gears need to match the motor gearing so that a rider can give help within the motor's operating range. However, that gearing emphasizes that the bike is not a hill climber. Changing the chainwheel from the 52 teeth to 48 would help slightly, but not very much.