New Zealand Student visa - Financial requirements

Can you explain the Income Tax Return (ITR) part in more detail in New Zealand?

Is the ITR requirement applicable only for one course or for others as well in Australia/New Zealand?

Is an income tax return (ITR) mandatory for visa applications to New Zealand, Australia, and the UK?

What is the total income required in ITR for these countries in Australia/New Zealand?

Will education loans be accepted as proof of funds for the visa application in UK/New Zealand?

Which countries have less strict or different financial requirements compared to New Zealand, especially regarding funding duration?

What is the financial criteria for sponsorship for a student visa to Australia or New Zealand?

Can I secure a visa if I show preparation admit cards instead of salary slips for private college employment in New Zealand?