I think where the accommodation is will, from the sounds of it, make more of an impact on your enjoyment than whether it is a hotel or villa. If you definitely feel you need shops, restaurants etc nearby to enjoy the holiday (a very valid standpoint!) then insist on that, as I can't imagine your in laws will actively NOT want to be close to amenities - at worst that won't bother them one way or the other. They can always stay by the pool in the villa/hotel if they choose to, regardless of the proximity of amenities.
I would try to discuss expectations beforehand, both with your husband privately and with the other couple - maybe have them over for a nice dinner for this.
And it's reasonable to say, in a cheery way, we will probably want our own space in the day as we all like doing slightly different stuff, and then meet up in the evenings and we'll plan one day out together midweek too - or whatever you feel comfy with.
A villa does, as others have mentioned, being a whole potential for complexity regarding who cooks, who chooses and pays for food etc - I have struggled with that one before when holidaying with my ex, his grown up kids and their mom! (Don't ask.....). We all largely got on much better than you would expect - in fact I ended up liking her more than I liked the ex in question, but still cooking became a battle ground as both she and the boys considered themselves expert cooks and took over the kitchen, whereas I love to cook sometimes too but felt pushed out.....
It could all be lovely of course, but you are wise to think this through. I just advise you discuss everything with them as openly as possible beforehand.
Good luck!