Student Visa Cancellation

Hi! I am currently a student in Malaysia but transferring to Australia soon on Feb 2020. I have some questions regarding the following:

1) My student visa expires on April 2020 however, I don't think I'll be able to cancel my visa as I need my passport in applying for student visa application in Australia. It takes too long to cancel which is 1 month.. I will be leaving for Christmas and will only be back here January to get my academic transcript but would not be able to cancel my visa as I have no more time... What are the consequences if I do not cancel my student visa properly?  I am not planning to work or study here anymore but Can I still visit Malaysia as a tourist? will they still allow me to come as a tourist even though I have not cancelled my student visa?

2) As I wont be able to cancel my visa, will it affect my student visa application in Australia?