Do I have to solder on the resistor? Nothing I've looked at as a replacement seems to carry the resistor on it. The tech is saying nothing is replaceable as the motor is no longer available. But he distinctly stated that this motor doesn't have a separate start cap. Perhaps he did not see two casings on top of the motor as opposed to it being inside.
You will have to place the resistor back on the new cap. In reading the label on the motor, it seems to say that internally, there aren't any consumer replaceable parts. That is why the tech is making that statement. Almost all AC motors have a start cap. Induction run motors won't have a run cap.
However, as Flyerdan is pointing out, the symptoms you are identifying are high current problems and making sure the load hasn't increased for some other reason, like a mechanical problem with the pump, needs to be ruled out. If you are confident that is OK, then you can keep looking at the motor.
Your motor has 2 windings. You should check the resistance of each to make sure you don't have an internal winding short or open. They should be around 12-16 ohms or thereabouts.
Lastly, and you probably already know this, and more for anyone else who may read this thread, capacitors store energy. If the caps have failed, they are usually safe to handle (shorted internally). If they are good, they can store line voltage. They should always be drained with a drain down resistor prior to handling. That start cap should be safe with the resistor between the two terminals, if still intact.