I am in a very very similar situation to yourself. I think a lot of the comments here are worse case scenario, dooms day, 0.001% chance of happening.
For our joint bank account I just sent a void cheque that had both of our names on it. They don't need to see all your bank statements.
My husband is on his second IEC visa as well. He very came here in March 2012, lived on his own until September 2012. When we filed our taxes in February he filed as single and I filed as separated because I was still waiting for my first divorce to be finalized.
I have ordered my GCMS notes which give you an indication on your files. And no where was there any mention of taxes, and status on the Option C or any of that.