A medium sized wire brush (Josco from Bunnings - in the tool secton) on a drill is the easy and gentle way to clean the hub face

The wheel bearings should be fine at that mileage - and they have to be pretty shot for people to notice
Some tyres make more noise than others and these cars don't have great noise insulation

I live in Sutherland and have always got good service from Kar Pro in Sutherland
(They have a Miranda outlet - I've never used that outlet)
Great Deals on New Tyres in Sydney for Small, Medium, Family, Performance, 4 Wheel Drive Cars.

Failing that, Pedders in Taren Point provide a consistent service
Pedders Taren Point - suspension, shock absorbers, brakes

Avoid Jax - very variable and pain in the arse
Worst example is a friend getting new tyres, drove away, didn't get out of their lot and onto the road, wheel came off