1. at the airport transportation center, you could take the bus N21 which will run along the Nathan Road.
2. yes, from Nathan Road, you could take metro to Tung Chung, where the station of Ngong Ping 360 could be taken. And then, it is suggestd that you go to Disneyland as early as possible. I don't think half day is enough for you to enjoy the park.
3. Firstly, please take metro to Admiralty station, at the exit B of which you could take the bus 629 to the Ocean Park directly. In the afternoon, please take the bus back to Admilralty and then walk along the Garden Road to the Victorial Peak.

Finally, from the peak, please take the bus No.1 to the StarFerry terminal at Central. Here, you could take the time-honored StarFerry to Tsim Sha Tsui. The Avenue of Stars is located in the walking-distance from the ferry terminal.