Hi HYPS,
Firstly, well done for considering university life at this stage. There is no harm in having a general idea about what you might like to pursue. However, I wouldn't worry too much about specifics like this at the moment. Or at least, there's no need to.
But to answer your question: I go to Monash and I personally enjoy the fact that I can just hop on a bus and be at Campus forty minutes later without changing. That figure changes a bit depending on time of day, time of year and so on. In saying that, I assume that changing once or twice wouldn't be horribly onerous, and might break up the journey a bit more.
Travel time is certainly something that you might consider when choosing universities, but if the difference isn't huge then I don't think it's a deal-breaker either way. The other things that you mentioned might also be factors. I also considered financial reimbursement and, importantly, gut feeling. But in your situation I would stress that none of this is particularly important at the moment; who knows what might occur in the next few years?
Best of luck with your eventual decision and future studies.

P.S. I spent a significant portion of my life training and playing essentially across the road from where you live!
[EDIT: Also, the walk to Engineering isn't too far. The campus is relatively large, but you could comfortably make the trip in quite a short period of time. Not worth considering, in my opinion.]