Will it be very crowded in Hong Kong Disneyland on 27 Nov? What is the weather like?

I believe many people plan their trips around Christmas, so it will not be very crowded late Nov. Don't worry!

At that time, it will be a little cool, with the average temp of 18C or around and in most cases, it would be cloudy. Some lightly rainy days may happen, but it will not have any negative effect.

how much the fee of private transport to disneyland?on nov 27
the guest arrive on nov 25 and how much the airport transfer to your hotel

Since you don't mention ur hotel, here is my general suggestions:
Airport to Disneyland: the taxi may cost 150HKD.
To the downtown area, the taxi may cost around 250HKD.
As for hotel transfer, you need to consult your hotel.
Have a nice trip!