Try other values of the resistors. How are the resistor values related to the gain of this circuit?
What effect does the open-loop gain (right slider) have on the gain of this circuit?
What happens if R2 is greater than the differential input resistance (normally 1 MOhm in this simulation)? Is the differential input current still small compared to the current through R2 in that case? Does the current follow the "path of least resistance"? Explain