You should include everything relevant to demonstrate and to support the validity of your marriage. If your joint bank account was closed, pull statements from the years (or months) prior to closure. The other items you mentioned could be sufficient; I've had clients with less documentation have their condition removed. Do you have any insurance policies where the other is the beneficiary? Is one of you covered on the other's health insurance plan or do you have separate plans? Do you have any children together? Their birth certificates are good evidence as well. How you two chose to file your tax returns alone is generally not a ground for denial the removal of a condition on residency.
I agree with my colleagues.
Business Immigration Attorney. For H, L, J, EB5s, PERM and EB1/2/3 Petitions. Call 800-688-7892 or visit www.ImmigrationDesk.com. Law Office of Anu Gupta. The advice suggested here is for general information only and not to be construed as legal advice.
They will expect a good explanation for filing separate tax returns. They will expect an explanation why you have no joint accounts. I suggest you see an attorney, together with your wife, to see what you can do.
The above is intended only as general information, and does not constitute legal advice. You must speak with an attorney to discuss your individual case.