I would be wary of using the government web link supplied by tail wheel other than a basic guide and never call them or email them with questions.
You will simply by the sounds of it be a secondary applicant on your wife's visa application, so not much for you to prove other than in a genuine and ongoing relationship with her. Australia do acknowledge de facto relationships but the relationship must be longer than 12 months old.
As for the visa application for you they will only care that you pass the medical requirement and character (police clearances) requirements - they don't give a rats about your employment or occupation history.
Skilled work visas are pretty quick to be approved and have a priority status. All valid and complete applications will be approved and good migration companies know exactly what and how to put in good compliant applications. The key is to have access to PAM 3 (the current departments policy on visa processing).
I am a very long term, very active member of that other forum and have a fair idea about a number of visas and processes.