There's great hiking in the hills of Hong Kong if you fancy that sort of thing. The Hong Kong Hiking Meetup Group runs hikes of varying difficulties most days, though it's potluck as to what they might schedule on the 2 days you're here.

The problem with local bars (and anything else that involves interacting with people and doesn't cater at least to some extent to expats or tourists) is going to be the language. How is your Chinese?

Jumbo floating restaurant is indeed tacky (and full of not German, but mainland Chinese tour groups) on the lower decks. But the western style restaurant on the Top Deck is quite reasonable (although not world-class by any means) and enables you to sit in the open air looking over Aberdeen Harbour.