Water - the additions are all for Melbourne water, which is pretty soft and lacking a little in calcium.
Nope - thats 0.11 g/L or 5.5 grams in 50L. it adds up to about 4.5IBUs from actual hops... the rest of the bitterness would be from the hop extract.
People's declarations that they can taste POR in fosters beers is, for the most part at least, misplaced. The vast majority of them (not all but most) have no actual hops whatsoever and are bittered exclusively with Pre-isomerised hop extract...
Yeast ... sorry, I cant help you. No homebrewing experience in this sort of fermentation. Fosters use a proprietary yeast that wont be available to you at all. Perhaps the Cry Havock strain from Wyeast which is good for lagers at a low temp and gives clean ales at higher temps. Or maybe a California Common yeast?? Apart from that, maybe a clean ale strain like US05. Start it at say 16C and once you see it get going, force it down to 13 or 14, after about 48hrs or when its krausening nicely, let it go up by a degree per day till you get to 18 or 19 and then hold it there till its done.
Me, I'd go with a Cal Common yeast I think... I had an anchor steam that I thought shared a few of the flavour characteristics that you would find in a crownie.
Like I said, this is just some info about how I'd go about trying to replicate a Crown lager if I was so inclined, how you translate it to a recipe is all up to you. The fact is that its probably not going to really taste like a crown simply because you dont have the correct yeast strain, and if its not the same anyway, you might as well just brew an Australian style lager without worrying about all the guff I have been spouting.