Re: Water proofing
Apart from the obvious, the engine & electrical connectors are pretty well sealed. I know the unsealed bearings on the idler pulleys don't like a lot of dirty water/mud, and the mechanical fan probably isn't best for deep water. The diffs, xfer case, and transmission all have breathers, located reasonably high in the engine bay on later models, but you could do better, and the rear breather should be extended.
Just remember that it's an SUV, not a u-boat.
The cabin is pretty waterproof, so that's good. The headlights could fill up with water, not being sealed units, but the stock boots are pretty good.
Mine doesn't get the opportunity to go swimming very often here in the desert, but it has had water over the bonnet with no issues. The clutch didn't seem to freak out in the deep water either - although I guess you are in Australia, so you don't have a proper transmission anyway ;-)
One thing I noticed after swimming was that the bottom of the airbox was damp (I don't have a snorkel) - I don't know if it sucked the water in through the pre-cleaner dirt dropper out thing or if it came in through the pipe in the fender. The good news is that the airbox design is brilliant the way the air is pulled up through the filter and a big space in the bottom of the box to collect water, sand, and any small animals that you might suck in.