JAJ Sure, if someone swears that they intend to live in Australia permanently, when in fact they don't, DIMIA generally do not complain. It is however a criminal offence to give false information in an application - so I guess its up to the applicant if they are comfortable to make a false application on which they are not likely to get caught out. Any applicant in this position should however be aware that such a statement has legal implications well beyond the DIMIA application and the criminal law. The Australian tax office will buttume that the person is domiciled in Australia for example and subject to Australian tax on their worldwide income. For someone with large amounts in a preserved superannuation fund outside Australia this can have horrific taxation consequences. Evidence of a change in domicile can also affect the applicable matrimonal law and will generally mean that the Family Court of Australia will apply Australian law to the marriage - which may not be what people not living permanently in Australia - particularly from community property law countries - would want. A change of domicile will also affect people's inheritance regime - and an application for Australian permanent residence would mean that a person would be subject to Australian inheritance laws - which might mean for example that their spouses relatives could make a claim on the spouses' legacy under Australian law - which may or may not be acceptable. Just a lot more to think about than swearing a stat dec that you intend to live in Australia permanently when in fact you do not, or just wish to have the option of going to work in Australia for a while.
The definition of member of a family unit contains a requirement of dependency. REG 1.12
So a grandma or uncle or younger brother who was a "member of the family unit" as defined in the regulations could come on a prospective spouse visa or a supported dependent visa, but not on a spouse visa..