For good fast food Hong Kong style, try Cafe de Coral.
When I went to HK in October 2011, I went to this place for lunch a few time. You get a huge deep fried pork chop, with veggies, rice, and your choice of tea (lemon tea, milk tea) all for $5 CAD.
You order your food, get a number, and wait for your number to be displayed on an electronic ticker tape sign.
A review of this restaurant:
Cafe de Coral Restaurant Reviews, Hong Kong, China - TripAdvisor
For nightlife, I highly recommend going to Lan Kwai Fong, near the Central district of Hong Kong. Great bars and restaurants there. Stormies and Zinc are great bars to go for drinks. Bands belt out good music at Insomnia.
La Baguette serves good sandwiches and pizzas.
lankwaifong.com