Most of the people who list their property for sale on there are legitimate, but finding the deal is the hard part.

He may also enable you to dodge potential bullets by pointing out small things like, "This roof will create a 20' tall attic" (Seen it happen on a job where the owner tried to save pennies by designing the house themselves), or "This window is too small to meet the City's egress code, which exceeds IRC requirements"

I'm unaware of any rules surrounding this sort of transaction since it's new to me but seems legitimate.

This enabled me to save quite a bit of money for the next investment which ended up being my primary residence at the time which was a 2 family so that tenant ended up paying 3/4 of my Mtg on that house.Having other people's money work for you can be a great way to build a bankroll and or free up capital for you to invest elsewhere!

This is certainly the case if one glosses over the risks, writes the strike price at an amount far above the spot price when the agreement is executed, or does any other similarly devious thing to try to part the tenant from what would possibly be a legitimate down payment if they waited and saved the money to put down.

Are they legitimate or scammers?

Is there a way we can structure the deal to enable him to invest?

The only investment properties I've seen go through were situation where the homeowner became a landlord and there was a legitimate hardship.

As long as it is a legitimate non profit and you aren't using that money to buy real estate - that's what your business is for.

I do not think the newbie sees to many legitimate deals like that.I really think nothing beats not being naive and desperate.