Any chance you can post a photo of what's asked with personal details redacted?
Based on what I see so far:
1) USCIS asks for proof of cohabitation. Do you have a copy or copies of lease, or mortgage? Do you have copies of IDs / DLs of you and your spouse showing same address where you actually live?
2) In terms of financial comingling... Did you submit joint tax return transcripts? The bank statements, were they for a joint bank account? Do you have any work retirement plans such as 401K? Did you include your spouse as a beneficiary on them?
Since you got RFE, I'd do what instructions for I-751 say as well as RFE. They tell to cover period from start of marriage until now. Throw everything in, from the day you married until today. All the old and new info. All pages of all statements.
What else is asked for?