HML or shorter term debt needs to be treated on a different level.

If I am doing it myself, I will have to run a 100’ cable from inside, but this will most likely be a technician job who can find a much shorter path through the window from outside.

I realize since seller financing terms a shorter which causes the monthly payment would be higher but I do have to ask, is that the norm that real estate investors go through with seller financing is to cash flow negative each month? 

I'm primarily looking for down payment assistance so I can purchase more in a shorter period of time.  

This way you get your offer out there to a larger audience and increase your chances of getting a deal in a shorter period of time.

There's always the possibility of a portfolio lender who might retain the note and make a loan with shorter seasoning...but I'm unaware of any.

So far, it seems the options are:(1) Treat them the same as those staying shorter than 28 days(2) Treat them the same as those staying shorter than 28 days, but require security deposit(3) Treat them as long-term tenants, sign a lease with security deposit. (4) Treat them as long-term tenants, check background, sign a lease with security deposit.My main question is that if they have stayed longer than 28 days and refuse to leave at the end of their stay, landlords will need to start eviction processes no matter whether they have a lease with guests or not, correct?

Getting a mortgage after is closer to a refi than a starting mortgage...and in most cases, unnecessary since the LC itself is a form of a purchase agreement...usually just over a shorter period of time. 

We’d be willing to stretch the commute out, and frankly would need to in order to purchase something we’re looking for but will likely need to remain within a 2-hour (1 way) commute of NYC for the foreseeable future.Alternatively, I’ve discussed the benefits of house hacking with my wife and she has reluctantly agreed to give it a go, but it would need to be on a shorter-term timeframe 1 to 2 years max.

I get that them bringing the lines to your complex may require significant outlay on their part, but that should be recuperated in a much shorter time than 8 years, so I don't get their insistence on this horizon.