Bi carb and bleach mixed together are recommended for grout mould, but I only ever use bi-carb with the assistance of an old toothbrush. Bleach is too harsh on grout.
I had problems with black mould growing on the silicone around the bath and vanity, but this is caused by the plumbers using the wrong silicone. It has to be replaced with the correct anti-mould silicone. It's easy enough to do if you have a steady hand.
In regard to bathroom taps and shower heads being difficult to fix, they normally aren't unless you have ceramic fittings which are supposed to last a lifetime, but often they don't. You can't just change a washer, you have to replace everything because it's all welded together in one fitting.
Quote:everything at Bunnings is crap ... nevertheless , it is handy
True. You could forgive the poor quality products if the staff had any clue about what they're selling. If they bothered to look at the product manuals - they might learn something, but generally most of them are lethargic and uninterested. You have to do your homework before you buy anything.