In order,
Employment - You will find that rates of pay are probably in the vincinity of 20k (roughly) less than Sydney. That is reflective of the percieved* reduced cost of living here.
The unemployment rate is high, but that tends to come from the amount of lazy people more so than lack of jobs. Therefore, if you are motivated and highly skilled, this should not be a problem. The BlueScope Steel, Port Kembla Steelworks is a large employer locally, both directly and indirectly, and due to this a lot of the Illawarra economy is often based on how they are doing. The University of Wollongong is also a large business/employer in the region.
*Cost of living - Housing cost is high. Infact, based on a survey of major cities in the world, it is ranked 10th least affordable...... You can find cheaper areas, though you will find those lazy people who don't care too much for anything about there. You do have a large range of area's to choose from though in a relatively small strip along the coast. So finding a place that suits your lifestyle should be easy.
Events/Nightlife - There aren't alot of big events here, most things are based around the local sporting teams in the NBL and NRL. They are both followed passionately.
There are plenty of cafe type places to go of an evening that are really good value. This is something that you would be able to work out yourself in time to see what suits your tastes. As for more upperclass places, there are both seafood and fancy restuarants around a plenty, and with the varied ethnicities around there are many types to choose from. There are pubs everywhere, and in the city of Wollongong there are many nightspots to go, from Uni hangouts, to well known night clubs and pubs. In saying that, Sydney is only 1hr drive away and there are more events there than you can poke a stick at.
The array of local beaches is great, there is one within 5mins of anywhere and everywhere.
Good quality food - depend on what you like but there are some nice seafood restuarants and fine dining places to go.
Public transport - There is a heap of bus routes that service almost every area. Trains run up the coast line, but can be hard to get to in some places such as south of Port Kembla when you are nearer to the coast. But in saying that, everything is only within 10-20mins driving distance.
Hay fever - I can't comment much on this, but there are some areas that may get more issues. Again I can't say specifically because you can go from the coast, to the farms within 10mins drive, so it can vary much.
I've tried to be un-biased in my comments but you will still find peoples experiences vary somewhat.
Hope this helps.