Floating Boat Dock - Need Installation/Grounding Advice

Hi, I have a floating boat dock, attached to shore via galvanized steps with boat dock riding up & down galvanized channels on the stairs. We had a used boat dock modified and installed so it has an existing circuit breaker panel and wiring for lights, outlets and boat lift motor (it was previously connected to land power). We have no connection to land power and currently run a gas generator for the boat lift motor. I am looking at installing a 200 watt system kit with 2 solar panels, a 100 Ah battery and a 1500 to 2000 watt inverter (plus all the other bits & pieces).
Question 1: Can inverter be connected to existing breaker panel (assuming inverter has A/C wiring posts)? Any items to watch out for?
Question 2: Does this system need to be grounded? If so, to shore or is there an alternative? To shore is up a stone cliff with approx 100 feet of wire and difficulty driving an 8 foot rod into rock.
Question 3: Any other tips or suggestions?