A lot of their deals are locked up from the mls.

When you know your market, you can identify a deal, lock it up and flip the contract easily.

It is simply there job to get a deal, and lock it up under contract and move it to a buyer or buy it themself.  

What if you sign a Contract and are locked in legally to do business with this guy?

I added a wall and a door that locks to the basement to separate the units.

I'd put an offer in though with contingencies (inspection, financing) to lock it in. 

I am still locking DSCR in the low 7's on 30yr FRM and mid to high 7's on ARMs. 

In this market, I would strongly strongly suggest in this environment structuring towards optionality (being able to BRRRR or flip in 4 months at project completion depending on the numbers) rather than locking in to one strategy at the get-go

Realize the rates are likely to change unless you lock something in very soon.

There's not enough cash flow there in your plan for the amount of principal that's being locked up, and in their plan they are just blowing the money on hookers and coke, metaphorically speaking.