Australia Post-study work - Post-study work visa

Is Australia or New Zealand a better priority for me to apply to?

Where will I get better return on investment (ROI) for studying abroad in tech in UK/Australia?

Are the countries UK, Netherlands, Denmark, Ireland, Australia, and the US good options for my master's studies considering immigration issues?

What are the country options and job market situations for UK, Europe, USA, Canada, Australia for freshers and experienced students for a PhD?

Can you explain the difference between the post-study work visa and the job seeker visa in Australia?

Is it true that Australia does not offer a post-study work permit after a 3.5-year course for a Bachelor's/Master's?

If I do not find a job within the six-month visa extension period, do I have to return in Ireland/Australia?

Are there options to stay in the country without a job or work permit after studies in Ireland/Australia for a Master's?