As soon as I took possession I changed that real quick and did it myself so I got full rent .

Get judgment for possession plus a money judgment.

Looking ahead to rehab work, and after doing my research for mortgage financing etc, amongst many requirements, but one in particular, i was told in order for me to get a mortgage for my investment properties, which will belong to my LLC, i would have to have the deeds in my possession to the properties seasoned for at least 6 months before being considered.

When you take possession, take a detailed inspection and photos and any damages between now and move-out can be taken from security.

The PM we contracted worked so hard begging the closing day, as soon we took possession of the property, that I felt it would be morally wrong not to share my experience up this point. 

You don't want a situation to occur where daughter gives notice and moves, but now dad has possession (with whom you have no legal contract) and is not paying rent. 

The tenant is also telling other prospective buyers that he only pays 550 when he is supposed to be paying 750.None of that really matters to me since the tenant is month to month and he would be gone once I took possession of the property.

Technically you can be forced to remit all collected rents to the former owner, because you were never legally entitled to possession.2) They can file suit against you and ask the court to declare the sale void.

Option 2 - Look up adverse possession laws in your state.

You (or the seller) *might* have an adverse possession claim.