This “investment firm” is likely some guy without the resources to buy your property.....this is a popular scheme (sandwich lease option) taught by the gurus for beginners to make money off your property.  

From what I can see, that seems to be a pretty clean, and popular way to sell a brokerage business like that!

With online portals being so popular now you should be able to see real time updates.

You're also in Moore, OK which, in spite of being a major tornado alley is also a pretty popular location... if the house hasn't sold for a year, there's something else going on.

It is a 30 yr fixed rate conventional mortgage from a popular bank.

I would say raise it but keep it realistic, so not a drastic raise or else it might affect the popularity of the place.

Blanket loan I know is a popular option but I don't know at what scale that is suitable or not.

@Jennifer Marshall The kItchen Is generaly the most important, not to the mention most popular room in a home.

If condos are popular in your area, they can be a great asset.

I believe a popular option right now is the Wyoming master LLC which allows other LLCs to live within in it even from other states.