In February the weather will generally be pleasant. A bit cool in the mornings and evenings but on a sunny day the afternoon temperatures can get warm. I haven't been in February, one of the few months I've not visited but even in December I was in shorts and T-shirts for most of the day.
It will be cooler in the mountain villages such as Soller or Valldemossa and in December a lot of restaurants were closed although many had notices stating they were opening again in February/March.
Palma is a beautiful city, one of the best in Spain and it's a year round destination. You'll be unlikely to encounter many restaurant closures, if any. You can easily spend a couple of days exploring Palma and fill some of the other time exploring the island. Parking can be an issue in central Palma so if you can find accommodation with parking or be located more on the outskirts you'll have an easier time of it.
Cala D'or is indeed a lovely town however it's very much a seaside resort and when I visited in December it was very, very quiet. Returned in June and it was a great bustling place with plenty of excellent restaurants and a lovely small cove perfect for young children to enjoy a safe paddle.
Pollenca is another favourite of mine but again, it's primarily a small fishing village and in February it will be very quiet. It has a lovely beach area but not much use at that time of the year.
I would stick with Palma.