Diane -
In my opinion, stay away from Sundays and holidays, and watch out for unexpected holidays. On one trip I was bitten by Pentecost Monday.
As to the chef doing a "drive by" to check the facilities at an unknown villa, you can ask that he arrange to do that prior to your arrival, which will help maintain the surprise.
Menu - Yes you can work it out ahead of time, which is what I prefer to do. Sometimes local events - strong offshore breezes and high seas keeping the lobstermen from going out - can require a "game-time call".
As to swimming naked in the pool, proper decorum would advise against it, but if you do then don't expect the chef to hand you a towel when you get out.
I highly recommend doing a chef's dinner. The romance value alone is huge. One thing that I have always said is that villa renters don't leverage their villas enough. We rent villas with million dollar views, and then use them as little more than bedrooms. Nobody loves the restaurants of SBH more than I do, but there is a lot to be said for a simple takeout roasted chicken lunch that is enjoyed poolside, or a chefs dinner, served poolside with that million dollar view that you've already paid for.
If you're not comfortable working things out with a chef that you don't know, and possibly with a language barrier (I don't know how well you speak French, but I do know that some of the chefs don't speak fluent English) then work through Premium IV. Premium IV works with several chefs. Jim, with his British heritage, speaks the Queen's English perfectly well. Vincent, with his French heritage, speaks French like the native that he is, but is also fluent in English.