VH-XXX,
Whether an Experimental, Restricted or Limited Cert. aircraft can fly over a populace area depend entirely on the operating restrictions contained in the Annex. to the certificate.
There is no "one rule fits all".
The great majority of "Experimental" aircraft are "Experimental Amateur Built", and after the test hours are flown off, almost always the same rules apply as apply to CASR Part 23 aircraft.
As to the airworthiness of "Experimental Amateur Built", the overall standard and quality of build puts many "factory built" aircraft to shame.
Tootle pip!!
PS: Have a look at the CASR 101 definition of populace area, of the three conflicting definitions in the regs., this is the only one that makes sense, ie; it actually has a rational safety basis.