Most of Magaluf wil be swarming with visitors, both families and singles. A lot of people will be concentrated in a relatively small space. Provided you can put up with the noise at night it will be fine. (I am used to peace and quiet) It is a very warm climate and as people inevitably crete rubbish, insects of all sorts just thrive on the situation. That's life, you have to put up with it; the majority are harmless. A couple of advantages are that there's lots to occupy children in safety and it is not far from the airport.
A good day out would be to catch the bus to Palma and then the the only train on the island. It passes some wonderful scenery through the middle of the island and ends up near the sea at the other side. You can take a tram to the pretty town of S�ller, once the capital when the French owned the island. Another suggestion; hire a car for a couple of days and see the north of the island it is really beautiful. I discovered some stables near Alcudia that rented me a horse for a day, and I had a great time just plodding around on and of the road.
If you are athletic then join in the watersports fun in Palma bay. Eveything from doghnuts and jetskis to windsurfing can be enjoyed, but be prepared to fork out a bit of cash for that. Majorca put a tourist tax on stuff to pay for the wear and tear damage to the island caused by the influx of visitors.