Does anyone have experience or know of someone who was able to obtain a DSCR loan with the seller carrying a second mortgage?

No.A wholesaler doesn't need a proof of funds letter.

You’ve got three levers: timeline, cash flow during rehab, and total carry cost.

I had to take a significant amount of their security deposit due to damages/unpaid late rent fees, so I obviously don't want them to get that back b/c of something I did technically/legally wrong in the re-mailing of this letter. 

Carrying on financing related activities for a fee, like providing loan commitments places you under finance regulations.

I have been driving for dollars and mailing letters to houses that look empty.

The precarious limb only extends over my property by a few feet, but a strong wind can easily snap and carry it into my property. 

I also received a letter from the county saying that my property is in violation of several health and safety codes. 

I have gotten an pre approval letter from the bank for a mortgage loan, seeing that the interest rates are high right now, it's looking like my room for profit is limited.

I know that because I have to deal with them every day.But your agents also deserve some blame @James McGovern for not catching that in the pre-approval letter.