Let's have a go here:
1. cost of living = depends on your standard. everyone is looking for something, but if i were to put something rough I'd say = studio, 1 bedroom can go avg. 35-45k aed per year. you'll find a bit lower and a bit higher. if its too expensive ppl tend to live in neighbouring city sharjah which is about 15-20minutes from the center of dubai except traffic can be a hassle.
2. weather = it is great in the winter with temps about 15+ celsius. we are in the middle east so you have to know the summers are really hot and humid also reaching 45-50celsius or more. on the plus side you have to note you could spend all day indoors where everything is airconditioned so its only the distance between your building and a car/taxi that you have to worry about
3. young expats live everywhere. there are some communities but i'd say anywhere really. again this is preference. you can go to real-estate agencies as soon as you arrive to hook you up with tours of whats available and meet your budget.
4. massive cultural issues not really. Women arent forced to do anything here. There is only one month of ramadan where you arent allowed to eat until the fast is over but thats about it. Truthfully you'll find the night scene here as enjoyable if not more then in europe and north america.
5. some expats learn arabic but most just get by with a few words. The whole city can speak and understand english except for a few I'd say. so you are safe .
6. There are no taxes here. everything you buy has a 4-5% tax already included in the price and its still much cheaper for items here then it is in other parts of the world.
Finally just remember that Dubai is the most westernized city in the middle east. You will see it as a very multi-cultural environment.
I think thats it.
Cheers,
D