1) Yes, it can...but...it will cause the transfer switch to operate which will transfer the power going to the RV to switch from shore power to generator.
2) Yes, you can use A/C #2 whenever you're running the generator...in fact, you should have a large switch somewhere that will allow you to switch to the rear A/C while on shore power (but that will shut off the front A/C).
3) No, if the generator is running, the transfer switch will be held in 'generator' position as long as it's running. Once you know the shore power is back on, just turn off the generator and it'll switch back to shore power.
But...turn off the breaker for shore power. When you know power is back on, shut off the A/C, shut down the generator, turn on the breaker. Just to be safe.
Not sure exactly how a '92 is wired, but my '94 has that large switch so I can switch between front and rear while on shore power, but when the generator is running, both work.