We are simply asking $200k for the house so I don't think this is an unreasonable price for the neighborhood.  

It would take an unlikely and unreasonable effort to match their results in very brief amounts of time, though they are the first to tell you that their results can and will be repeated by investors time and again.But recently, I've come to adopt a more grateful worldview.

@Nick Versetto, if I had to deal with a borrower's attorney who didn't understand the deal or made innuendos that I was breaking the law or charging unreasonable fees, etc.

But, understand, you'd be taking a cut of your partner's money, so it's unreasonable to think that they'd be too happy...No easy answers here.

Is it unreasonable to be able to bring a down payment, and then use a conventional mortgage to get the property with a pre-approval letter?

With so many investors articulating their partnership terms of agreements to suit their unique goals and needs, is it unreasonable to think that we may be able to structure our agreement so that it would address many of the inherent concerns our unmarried status brings to the table?

The point, oh greatest of real estate sages, is that we still wanted to find a way to isolate the properties within a legal structure that would further insulate the growing portfolio of RE assets, a not unreasonable aim in a situation where a three to five million dollar blanket policy could prove small change in the right circumstances, especially here in the USA with its bevy of piranha lawyers waiting for any given opportunity to stake their financial claim.

Am I being unreasonable by refusing to go past the extended closing date on this property?

And, by the way, I do not think that is unreasonable.  

Your plan doesn't seem unreasonable.