Confusion about voltage at negative terminal of capacitor
The negative plate of the capacitor is connected to ground. Therefore, if you ask for the voltage at that single point (rather than explicitly with respect to some other point) then the answer must be 0V. This point is always at 0V, by definition, because it is connected to ground.

You are correct that the electric field on the capacitor causes charge to flow from the negative plate to ground. The amount of charge exiting from the negative plate is exactly equal to the amount of charge that enters the positive plate, so the entire capacitor structure remains charge neutral. As voltage increases across the capacitor the voltage across the resistor decreases, which means that the current must also decrease. Given enough time, the voltage on the capacitor rises to be the same as the supply voltage. At that point the voltage across the resistor falls to zero and current flow also falls to zero.