1) yes you can jump through cloud.... parachutes must be open by about 4000 feet clear of cloud depending on type of jumps and location.
2) yes they can decent through VFR airspace, hence why there is a little symbol that means there is parachuting in this area that many people take no notice of and the very same people tend not to monitor the area freq...
3) Cloud manual is company specific and even aircraft specific... pilot's must hold an instrument rating
4) Blatant liar, you are an idiot, the operator at st kilda is very professional and senior pilot is a good guy with lots of experience, have a read of the link below
for all of you arm chair experts and bar stool lawyers.... here is and interesting link
About Cloud Jumping - Australian Parachute Federation
A simple google search these days save many a person from looking like a D!LL