From what I have seen, the multi-unit is a safer option because I have two + units as opposed to technically only one.

You need to study more.Now if you mean they are giving you 30 days to close the sale then if you don't close technically your deposit can be at risk but usually, you ask for an extension of time. 

I dont say lender because we  only JV but we bring the type of capital your talking about.so private capital that is sophisticated enough to go into spec building is not going to be any cheaper than HML and could very well be more.It can take some time to find banks that will play but it can happen as they are getting back into the game.If you have the three C s and track record I would be pounding on every small commerical bank in the Vegas area.But franklyright now bank rates for  me are 6.5 and 1  no junk fees just appraisal and I only have to appraise one model if its going in the same community. 

They were probably just hoping you would not be sophisticated enough to call their bluff and are trying to scare/blackmail/extort you into paying their ransom fee (and randomized the number to make it sound more official).

@Sinil KimBusiness skills are more important than technical skills in real estate or any other business.

Also consider, that if they sign the lease with 4 tenants, and then add another tenant, they have technically violated/voided the lease, and should be made to sign another lease or face eviction. 

There are motivated segments that aren't sophisticated and could be overwhelmed at the idea of doing everything they need to do before listing their house. 

How many days are we technically suppose to give this individual to leave?

So technically if you do sign a personal guarantee, it will affect your DTI

You can technically make as many deposits as you want, but really the less you make,  the cleaner it looks.