Dover to Paris Flight

Do you think this is a good option?

No, taking the train to London and then catch the Eurostar seems like a much better option in my mind. It will most likely be the fastest and cheapest option.

And no, Gatwick is not the same distance as St Pancras when you consider travel time.

Now that everything is booked, I guess you might as well stick with the flight. Vueling flights are not refundable anyway; the best they offer is flight credit as far as I know. Make sure you purchase the luggage allowance that you need in advance, as the base fare does not include any sort of luggage beyond a tiny personal item (barely the size of a laptop bag), and paying for luggage is much more expensive at the airport.

Thanks. We booked the Optima Fare for $330 for 3.

Even if the tickets aren't refundable, can you get your money back if you cancel the car to Gatwick? If so you need to compare the price of the train to what you would get back from the car (and any money saved from not having to travel from Orly to Paris), and the fact that a voucher with Vueling can be useful.

You don't mention when you plan to travel, but a ticket from Dover to London bought in advance costs £7 and a Eurostar ticket can be found for around €70. It would also save you about an hour of travel time.