One suggestion would be to visit the Taronga Zoo in Sydney. In my limited experience I would have to say it is the Zoo with the most fantastic views in the world. You take a ferry across Sydney Harbor to get there, then can go up this hill in a cable car, and slowly wind your way down the hill while looking at all the crazy aussie animals. The whole time you have a magnificent view over Sydney Harbor!

Unless you have weeks to spare I wouldn't bother spending several days at Uluru (Ayers Rock). I was there a couple of months back and we arrived there early evening, stayed the night, went to the rock the next day, then stayed one more night and took the noon flight back to Sydney. This included 4 hour drives to and from Alice Springs. If you were prepared to pay quite a bit more and fly straight into Ayers Rock you could probably do it in even less time. Going and seeing the rock, taking a walk around the base of it, and then possibly climbing it are the good things to do IMO. Beyond that you would have to be really interested in rocks to stay a lot longer. Just watch out for the damn flies...

Hmm, actually I would definitely recommend being there for at least one night though, as the view of the stars and the milky way is absolutely stunning. Of course if you go to Fiji or Tahiti you will get similar views. Nothing beats lying in the warm water on those island late at night and just staring up at the stars!

On that note, I haven't been to Tahiti, but stayed out on an island in Fiji once. I really can't imagine there being any problem about the gay issue at all. If you are having sex out on the beach or in the restaurant it may cause a stir, but beyond that I can't really imagine a problem. Maybe you will get the odd look now and then, but that will happen anywhere outside of the US where people have had less exposure to these issues.

Have a great time, and let us know if you have any more specific questions!