are there bus from rambler oasis hotel to tsing yi mtr station aside from the hotel shuttle bus?

As for your questions, here are what I know:

1. You can walk from your hotel to Rambler Crest Station to take bus no. 88F and get off at Tsing Yi Station Ground Floor Transport Interchange. Upon arrival there, you can easily find Tsing Yi MTR Station, which is within 200m from your drop-off spot.

As for the ticket, kid between 3 and 11 years old gets 50% discount. For kids under 3 years old, no ticket is needed.

2. I'm afraid there is no a MTR station within walking distance from your hotel. Kwai Fong MTR Station and Tsing Yi Station are the nearest ones.

3. To Disneyland, you need go to Tsing Yi MTR Station first, by hotel shuttle or bus. There you can take subway Tung Chung Line to Sunny Bay Station, where you can easily transfer to Disneyland Resort Line. It can take you to your destination directly.

4. At Tsing Yi MTR Station, you also need to take subway Tung Chung Line to Tung Chung Station. Then you can find the terminal of Ngong Ping 360 Cable Car.

Thanks Cimon, would you know up to what time does bus 88F operates? how frequent is the trip daily?

If i would be going to the night market, what time should I depart from the night market to catch the last mtr going to Tsing Yi and the last bus 88F going back to Rambler? By the way where is the best night market you could suggest?

It operate from 6:50 am to 11:30pm. In general, there is a bus every 10 to 30 minutes.
For the night market, which one do you refer to? Gerenally speaking, it is suggested to leave around 23:30 and reach the MTR station before 24:00 at midnight.
I think Temple Street is a good night market which is near Tsim Sha Tsui area.