You said in your post  "If the notice was delivered by mail then the notice period begins when the Tenant actually receives the notice."

Use financing but streamline contingencies and shorten contingency periods.

He uses poorly thought through methods, I've listened to his "methods",  Thus, he has the high amount of  Due On Sale called in a short period of time. 

What is the time period required before refinancing?

Let's assume that the neighborhood is a C class and the median income of the city is greater than 3X of the market rent.Here are some of the considerations I've come up with so far:- Units are in need of renovation and capex is too high or not available- Unit quality is not the same as market - Seller is worried about losing tenants due to increase- Vacancy rates are high or filling units have been difficult- Rent increase would take multiple increases over multiple lease periods to get to market rate if seller is trying to retain the same tenant- Seller inherited property and just want to liquidate- Seller needs to liquidate quickly (financial burden, sickness, quick exit from land-lording)It seems like I might be missing a warning sign about a deal if they are selling with current rents that are under market; but again, this seems to be most of the properties I've underwritten.And in the same vein, what should I be worried about when purchasing a deal with under market rent with the intention of raising them after purchase. 

These leads were very unresponsive and may pan out over a longer period of time but the time involved is just not worth the effort.  

They legally have to have this document filled out if they pay you more than a certain amount over the period of 12 months.

I have clients doing 1 a quarter thats about the slowest to others that will go on a mini tear and I will help them buy 5 or 6 over a 45 day period then they go to work.But generally my busy folks will do 15 to 30 plus a year..

Also, I believe I saw somewhere that the mortgage won't count against the original owners DTI after a period of time if they show someone else is paying the mortgage.

You could negotiate terms such as a lower interest rate or interest-only payments for a set period to ease your upfront burden.Lease-Option Agreement: If the landlord isn’t ready to sell outright, consider proposing a lease-option where you continue renting for a set period with an agreed purchase price.