And look at Normandy...there wasn't a Marine within 6,000 miles of that beach. It was run by the Army. Granted, they had some experience from Africa and Sicily, but in the end, coming out of a boat onto a beach is one of the most militarily unsound maneuvers you can take part in. Experience is not necessarily what wins the day.
As far as Navy, they have more ships/boats than the US Navy. Granted, we have them beat with overall tonnage, but they won't try to beat us on the open seas. They have a lot of boats which can make the channel run with land based forces nearby to provide air cover for them. It would be our naval power against their landbased air power (including land-to-ship missiles).
In the end, Taiwan needs to have a rifle and ammo in the hands of every able bodied person, and they need to quickly distribute thousands of man-portable weapons to take out military vehicles and aircraft.