For Q1 The op-amp is an amplifier if you have a signal of 10V and an gain of 1, your output will be 10V that is true if you have no load, nothin conected to the output od the opamp. If you have a Load conected to the output of the op-amp but that current in the load is less than the maximum current of the op-amp the output will be 10 V. But if the current try to be more than the maximum, Vout will not be 10V.
For Q2, if your input signal is 1v and your gain is for example 4, your output will be 4V, and if your RL = 1k Ohm your current will be 4V/1K Ohms = 0.004A. Rl is the resistance conected to the output and GND and is of 1,000 Ohms.
For Q3, Ok R min