From the description you gave of your desired location, I would not think that Kassiopi, would fit the bill.
To my mind, it is what I would describe as a town, although the tavernas are fine, there are also quite a few of what I would call music bars, which can sometimes be quite load.
You might consider San Stephanos Sinies (NE)
There are 4 tavernas, all with a different feel and atmosphere, 2 bars, which do play music, but not too load, 2 mini markets, 2 tourist shops, 2 hire boat outlets and 1 tourist office. The village is at the head of a sheltered bay, often used by sailing flotillas for an overnight stop. All the accommodation is self catering villas and appartments, many with pools. The companys that let that I can think of are CV Travel, Meon Villas, Something Special and Simply Ionian, there must be others but I cant think of them.
You might also consider Agni Bay, with 3 tavernas it could suit the bill, but there is not very much accommodation directly in the bay. And there is no village as such, but Kendroma village is just above it on the main coast road with one Kafeneon and no shops.
I'm sure you'll be inundated with alternatives.