1. Victoria Bay of Hong Kong(https://www.travelchinaguide.com/attraction/hongkong/victoria-bay.htm) is a harbor and the Avenue of Stars is a pedestrian street located on its north bank. From Maple Leaf, you could walk to visit the Avenue of Stars in the morning and then take the star ferry to Central. Here, you could walk to the Victoria Peak. Suggested that you take the tram up to the Peak, where the Madame Tussauds is located. In the afternoon, you could visit around Central, Wan Chai and Causeway Bay, also do some shop and have dinner. At night, you could take ferry or metro back the Tsim Sha Tsui around 19:30 and then enjoy the wonderful A Symphony of Lights, Hong Kong(https://www.travelchinaguide.com/attraction/hongkong/symphony-of-lights.htm) on the both side of Victoria Bay.
2. Yes, there will be a large number of travellers there since the Christmas. If possible, delay your visiting to the next day.