As to how they filmed it, I think you are right. I doubt they placed a camera in the DS (with a cameraman and sound equipment and whatever else). I expect a lot of it was done on a sound stage, or they had special effects to put the background in. Hollywood has to fake so many things. After all, how practical is it to put a movie camera in the back of a DS - especially with late 50's technology? Amazing that they can pull off so much.
As to cutting down the combings, it depends on if you want to race or day sail. For some reason, performance or another, the DS II doesn't seem to be raced much at the regional level and higher. I've never heard a straight answer as to why, except that they are slower.
"And why are they slower?", I asked.
"They just are." I heard )
If you race a DS I, I'd think you'd want to make it easy on the skipper and crew.
But the combings and floorboards on an old DS, when they are taken care of, sure are handsome. In a way, I miss that age when there was more wood in boats. But, taking care of all that wood... Well, there goes a huge chunk of time!
Keeping the gelcoat looking reasonably good, that's enough work for me. Not that I succeed at that very well, mind you.