Does he qualify on his own?

Improvements on property you own do not qualify.2.

Plus, if you aren't able to get approved with what you've got now in terms of savings, credit, etc. you can learn on what you need to qualify so you know what to be working towards. 

I recently came across 1 acre asking for 314k in a very good residential and growing location, so the current owner has added 4 manufactured homes with 4 electrical meters, 4 septic tanks and only 1 water meter for all 4 homes, the homes are sitting on partial slab and partial pier & beam, he also added 2 storage sheds approx. 380sqft with the intention to make them ADUs they are still only the shell so I would have to get those ready to live in, so currently the 4 manufactured homes are being rented and bringing in 2800k a month, 3 of the homes are needing some TLC which could increment rents and possibly get me at 3600k a month, also being a 1ac lot this still leaves about 12,000sqft of raw land where you could build etc.So that is on the good side now the things I did not like so much, the lay out is poorly executed to where it makes it looked crammed up and not professional but it could be fixed.Another is that in reality there is only 4 livable units so that qualifies under a conventional loan but since they're are 6 units on the property the banks are wanting to take it as a commercial so we would have to move out the 2 storage sheds out in order to close as conventional.Another concern, technically you are only allowed to have one manufactured house or single wide in your property according to what I know but I know it could change according to zoning which I will investigate, so my question is has all this been accounted for and if so how can I verify it so it wont leave me in a bind further down the road, I currently asked my agent for the appraisal of the property to see if that might verify.Any recommendations?

They said they will not take rent into consideration and declined me because they are using the mortgage of that new loan, my current mortgage and HELOC payment off of just my income now, which is dumb because of course I can’t qualify.  

i wouldn't tell you where you should move since i don't know you.also, a lender would be in the best position to advise whether you qualify for a specific loan. 

I think this is one of the only ways to protect a sellers future ability to qualify for a mortgage. 

They’re requesting what feels like an unreasonable amount of information, and the demands keep escalating.So far, they’ve asked for:A video tour of my home officeCredit checks on me and my partnerCopies of the deeds for every property we ownA copy of my partner’s home lease and utility billsBusiness phone billsA signed letter from the bank verifying our accountsBank statementsHonestly, it feels more like qualifying for a loan than trying to become a customer.

You can still qualify so long as you have verifiable income.

Not having experience qualifying prospects I would think that the leads you would get from here, if any, would be..... challenging.