I just bought this game, however my mouse is broken so I'm forced to use touchpad. is there any way to control/rotate camera without using mouse?

I think there is no camera movement by using keyboard implemented by default in game. The only option for you are some mouse movement emulators but I've never used them so can not recommend any.

ah too bad. okay then, it seems I must buy new mouse.

I wanted play this on the the way in the bus with touchpad, but because of lazy developers is not possible.