I too want to know on these.
For me:
Employment: It would be tedious for submitting payslips. Yes i cant get it for previous employer. So i am thinking that they should be ok if we get past employer's experience letter and one letter from current employer.
Rental: I have rental agreement but its kind of old and only for one year till 2017. Not sure how this will be enough to prove rest of the years in the same place since my apartment office doesnt renew the lease but allow me to stay. I lost the yearly receipts/letters somewhere hence thinking i am left with getting one letter to cover all duration along with agreement copy.
Are they asking for additional documents for all online-test people? is it a new process change?