I live in Australia at the moment , I came to Australia as student and graduated last year. Then got my 189 invitation on 23 October and lodged it with all documents except medical. I will probably book medical test tomorrow
Anyway, as of now, this is my third oz visa and I have been always treated very well by case officers; they always asked me to send any related documents through email. So be optimistic, you'll be fine!
Also I am just wondering why you want to upload your work payslips! It sounds a bit odd, because you only need to upload your assessed work experience done by related Australian Organization. For instance, ACS is in charge of assessing work experience for IT applicants. I have never seen someone upload payslips!