Lenders use the DSCR as a way to measure a property's ability to generate sufficient cash flow to service its debt obligations.

Do they need coverage that is sufficient to fix/repair/rebuild the home due to their negligence?

One of the questions you might ask is whether there is a quantity discount, some are not readily advertised but may be available.

We do this for all of the mechanicals when purchasing a property, and set aside sufficient reserves.

At first, I thought of developing my own spreadsheet that includes the products I need for each of the units, the purchase date, the quantity, etc.

My quick google search shows that a 30 day notice is sufficient for an increase for rent.

Current rent he's paying is much lower than my rent, but income seems sufficient to pay my rent.Income is 3X month's rent, but he's a business owner so there's no pay stubs or anything like that to verify that.

For all my time listening to the BiggerPockets podcast (and even working with a lender on a triplex a few years ago), this is the first time I've heard of this, which is a testament to how much more things I have left to learn.Correct me if I'm wrong, but the self-sufficiency test for 3 or 4 units funded by an FHA loan means the maximum mortgage payment cannot be more than 75% of the total rental income, correct?

In this one case given the huge liability there may not have been sufficient insurance to cover the loss as there were several dead and injured. 

We think it’s important as it allows us to check for Non-Sufficient Funds (NSF) issues and to determine if an applicant is living paycheck-to-paycheck.