Why do you want to suspend it? Are you travelling? Also, are you within contract or outside of it?
I don't think Optus usually allow you to suspend an account but I suspect if you're out of contract they'd make an exception rather than you just cancelling and leaving them all together
It depends. If you have a wifi router, where you are using a postpaid sim card inorder for your wifi to work, then yes it can be suspended. Its $5.50 a month and if you are in contract, however long your service is suspended for, thats how long your contract will be extended for. If its Wifi for your internet service then no it cant be suspended.