ky0218

They both have the same date when u became permanent resident.

I think the reason that u got a rfe is you didn't submitted the official tax transcript from irs.
You only submitted 2012 tax transcript which is filed seperatly and 2013 1040 which they always reject.
You tax evidence is weak. I suggest you to send the tax transcript and other stuffs that they want in the rfe letter.
Also write a cover letter explaining you situation just like what you wrote in this post.

order the tax transcript and send it in.
Any bills(like cell phone, electric, car insuarance) that have either your name or your spouse name with the same address.
Highlight from the bank statements that who pay what bills and explain in the letter.
This would show them that the couple are paying bills and living together.

i dont think getting joint account now is a good idea. You shoud have the joint account that span ur 2 yrs marriage.
Any uility bills? I would try to write a cover letter explaining why you dont have these things.
And try to get people to write letters for you and get it noterized.(at least 2-4 since you dont have much evidences)