I have 2 fan tails which I have had for nearly 6 years now and I'm not sure you can really say they make good pets as they don't really do a huge amount and you can't really interact with them. But that being said they are beautiful, interesting creatures and I find them very relaxing to watch. They are in a glass tank in my office as I thin they make for a calming environment. I think if they are a first 'pet' for a child they are a good idea, as it will teach them to look after animals without costing you a fortune.
I don't think there is anything wrong with naming them, unless you have loads in a massive tank! Then it's just hard to work out which is which anyway! As I only have 2, and one is black and one is gold, its nice and easy to know which is which. They are called Dolly and Ozzy after my fav and my hubby's fav musicians.