Dubai area and "car vs. taxi"

Hi all,

we are stopping (for 2.5 days // 3 nights) in Dubai on our way to Oman. We are a family of 5 (2 adults + 3 kids 5/8/10). I'm currently trying to find out what's the best way to stay and get around in Dubai. In most cities across the world we usually rely on public transport and walking, but I'm not sure if that's the best for Dubai. It doesn't come across as the most walk able city.

As we are 5 getting a taxi/uber/.. is not always easy as most only have 4 seats of course.

So basically 2 questions:

- Whats a good base for us? The plan is mostly sightseeing (Main sights, Burj Khalifa, Aquarium, .. things that are good with kids). Close to a beach would be nice for the kids of course. One thing i noticed looking for Hotels, they are quite expensive.. and maybe I'm just not used to it but 300€/night is already quite expensive imho ;) At least it should not be much more ;)

- Transportation : Maybe connected to the area of the Hotel. Whats the best way for getting around? Is the public transport good and "dense" enough to reach all places easily? Or is it better to rent a car and drive everywhere?

Thanks a lot