The new owner's application with the mobile park office was denied after we made that transaction and she told me it was because she was new to the area and therefore unemployed at that time.

However, my question is if we need to file a claim in the future, will we be denied because this is a duplex and not a single family home.

No you can't charge a pet fee but you can hold them to the same maintenance guidelines as others and you can ask for references and deny if they have poor animal related references.

This same lender also told me that if I own multi-family rental properties and I try to get FHA financing for another multi-family to live in, they may deny me.

Can this be a good enough reason to deny their application?  

Your rental criteria should be what the standard is kept to.Either they have a Soc Sec Number and qualify or they don't and don't qualify.You want to rent to someone that's not in compliance,, then that's up to you.Don't make things harder for yourself than what they should be.No experience renting to undocumented,, but lots in denying because of invalid Soc Sec #.. or none at all.

I have already been denied from 3 hard money lenders with a credit score of 710.

We had agreed on a price and I had already gotten pre approval for a loan amount that exceeds the sale price but when the bank found out it was a half plex they denied my loan.

Fortunately, the bank denied the transactions and issued me a new card.

Can they deny my payment and still foreclose?