huit

I'll tell you where to have the best 港式点心... HK of course

中式???  日式?? You come all this way to Sydney... and all you want to have is 港式点心... ? Dim sim is pretty much the same everywhere, similar to HK, just don't expect HK prices.

Try some local fine dining at the Rockpool (need to book), would be nice if you could give Tetsuya's a try but you had to book at least 3 months ahead, or Marque at Surry Hills for a degustation.

For Japanese/Aussie fusion, Rise in King's X used to be good, as was Kobe Jones, not sure what the best place is for Jap these days, I think Rise still has discount degustation course on Tuesdays... not sure.

Dessert cafe - try Lindt Chocolate Cafe in Martin Place or Darling Harbour, Guylian Cafe at The Rocks

Great Southern Hotel is $#!+ but I guess it's reasonably priced. Public transport is ok in the city (a car would be good if you want to head out to the suburbs - it's just not HK), just buses and trains, try taking the light rail to the fish market if you love seafood for freshly opened oysters, sashimi etc etc, just be careful of those crazy seagulls.

Have fun!

huit

Ah... didn't know what your budget was

Makoto near World Square is good for sushi train,  also in the area is Din Tai Fung if you like Taiwanese style Shanghai dumplings. For proper Jap meal, Sushi Tei near Chifley Sq or Masuya on O'Connell are good.

There's a few HK style cha charn teng near Chinatown, don't know their names, but hard to miss. If you stay in the city finding the food you want won't be a problem so no real need to head out.