Thanks for the replies everyone! Very helpful and reassuring to read these.

For interest rates, my concern is if something like 08/09 happens again where they shoot up to 10+% for several years. Given that we are in one of the longest bull markets in history with interest rates current at an all time low, it seems like the risk for that is reasonably high over the next 5 years. It means a weekly repayment of $454 would be closer to $1000 which would be pretty hard to manage. That's why my thought on fixing the rate for as long as possible would reduce that risk if something were to happen in the next 5 years. I'm obviously all for a lower interest rate, but would like to hear your thoughts on the risk behind it if there is any.

Also, how were you able to get the cash bonus'? is the 10k from switching to different banks?