if you intend to continue your PhD at Monash or any Australian universities, then go on and do the Honours year. I have seen a lot of Honours student progressing to PhD straightaway (provided your supervisor allows you to convert you from a Master's student to a PhD student). Pls inform your supervisor of your plan.

For 1, yes it depends on your SV and the Uni

For 2, try to get sponsorship for your Honours first.

For 3, for Australian PhDs, they always prefer you to have an Honours degree or at least a Master's by research degree. Definitely not Master's by Coursework. If you have taken the Master's by coursework, they might ask you to sign up for a postgraduate diploma in research programme as a prerequisite.

For 4, actually it varies from unis to unis, just that Australian PhD programmes tend to be more stricter in accepting students without any research background.

For your last question, the Honours component in an Australian undergrad programme is an additional one-year programme, which is different from UK/Malaysian honours degree programme. In UK/Malaysian honours degree programme, there is no separate Honours programme like the Australian programme. Furthermore, the research project in the Australian Honours programme is more demanding compared to the UK/Malaysian final year honours project.