Hey guys, I really appreciate your inputs even though some of that could be repeated, but since I am not familiar with the city and with the names etc, I have to go through all of the posts once we are close to fly and prepare notes for myself. I think I should look for an off-line app so that I can use there an not get lost.
It was a good point that it could rain and I should be thinking about that too. I know that 5-6 hour max is nothing to visit a couple of things in a metropolitan like Melbourne, but this is just a layover and we had to take this flight so I look at this as an opportunity and I have realized having long layovers is actually good. What we want to get out of this is just to see the city, see people and walk around a bit and see the atmosphere, see how people treat us and how the whole system looks like this. It is our first time in Oceania so we are visiting a different continent for the first time so whatever we get is a bless. So if we can simply check CBD out, I think we can see some vibes there and that should be pretty much enough. The whole thing is to understand whether we should go back there sooner or later and spend a lot more time. Believe me, I have been to countries for a couple of days and I have been like that was waste of time, so people matter and it is not just buildings and views.
Again, I appreciate all of the input and in terms of food I have a very strict diet, I don't eat meat except ground beef if well done, or chicken breast, no pasta, no sea food, no Asian food and the list is long enough to make you feel this is weird. That is why I usually go with vegetarian options or anything that is safe to eat. So I am not the person to get excited to try local food unless I make sure it is something I can eat. I heard there are variety of restaurants so I hope we will be good. We want to grab something quick if we rush or sit down and enjoy a 30 min while taking rest if we were tired. It all depends on how we feel so food will not be our concern in a 5-6 hour visit.

