If you're there in time, there's a light show every evening at 8 pm, but it's best seen from Kowloon. You could catch the MTR from Pacific Place to Tsim Sha Tsui (you'll need to change lines), get out and walk to the waterfront, and enjoy the show. Once this is done, you could catch the Star Ferry back to the island. If it's a clear night, you could head up to the Peak.
If you'd rather see the view from the Peak during the day, I'd suggest getting to the Peak Tram station early, as queues can be quite long. Note that the haze is HK can be quite dense (there are apocryphal stories of people losing golf balls due to the low visibility), and it is definitely not worth heading up if the smog is bad. If you cannot see across the harbour, don't go up.
Pacific Place has a pretty good shopping mall; the International Finance Centre (IFC) is more upmarket, and you could catch the tram near there, or the MTR. Soho (south of Hollywood Rd) has some interesting antique shops and galleries, and is packed with restaurants and bars.
If you're going to have some additional free nights after work in HK, I'd suggest heading to Lan Kwai Fong and Soho for drinks and dinner on those nights, and rather than eat there on your free day, would suggest you catch the bus out to Stanley, on the south side of the island. The view from the bus (sit upstairs on the right hand side) is great and it's very cheap; a taxi doesn't cost that much either, compared with Australia. In Stanley, there's a small touristy market, and a beachside promenade with restaurants and cafes. It's quiet and pleasant, and not congested.
