Finding the total impedance and voltage across open terminals
Your total impedance is correct.
However your voltage divider is wrong. The correct voltage divider is VL = (j40)/(Z3)*Vx where Vx is the voltage accross Z2 and Z3.
To find this voltage, you  can use another voltage divider. Vx = (Z2//Z3)/(Z1 + Z2//Z3) * Vt.
To answer your two questions:

The &quot;total impedance&quot; has no real meaning. Rather we will speak about a total impedance accross some terminals. The input impedance is just the total impedance accross the input terminals. It depends on where you consider your input terminals are.

It depends on what you mean as &quot;80V&quot;. 80 VRMS is still a voltage, but is different from for example the amplitude of your signal. Assuming you are speaking about a sine wave, you have the following formula: A = sqrt(2)*VRMS where A is the amplitude of your sine wave.