Having hosted exchange students and been one myself, I can give you some tips.
First thing: the cinema is NOT a good idea for the first few weeks, simply because your student will be getting used to hearing English all the time and everything will be overwhelming. However, this doesn't mean you don't need to enjoy good films - get films with subtitling in German or English, set up a movie night in your sitting room, have a few friends over, some snacks and drinks, and chat for a while, and then turn on the film. That way everyone can enjoy it.
The stuff you do with your student can be fun things you both enjoy. Rather than assume it's all on you, why don't you ask your student what they like doing, or if there's anything specific they want to do while they are in Australia? Have some leaflets or websites available that you can both look at, and offer to take your student to those places. He/she may want to learn to surf, for example, or do a lot of swimming - Bavaria is way inland, after all.
A trip to the zoo might seem fun and childish, but learning about animals is familiar territory to everyone - and there reassuring in a country far away from home - and given the huge number of dangerous creepy crawlies Australia has in comparison to Europe, it might also be practical.
The fact is, hon, you're going to have to modify a few habits while your student is there, and get off your backside and away from your computer for a few hours every day. But these things can be discussed, especially if you have some kind of obligation to be online for so long (and gaming doesn't count).