I've been trying to get my agents license for a long time now and due to unexpected expenses and health issue it been nearly impossible to save anything.

But if you ask me what is the most important to have when acquiring multiple rental properties with multiple tenants, I would say that the number one priority is having a very strong insurance policy structure as your first line of defense for any unexpected/extraordinary events.

Arguments for a 30 year loan: (1) You lock in your fixed payment in "2018 dollars" for the next three decades, when that $700 will be worth a lot less (Jason Hartman calls it "inflation-induced debt destruction")(2)  Since your payments are lower, you have increased cash flow that can be used to deploy capital into new projects(3)  If unexpected expenses arise (personal or business), you have an immediate source of regular cash flowArguments for a 15 year loan:(1) increased equity over a shorter time horizon(2) cheaper interest rate(3) owning property "free and clear" still in your prime years and the lifting of psychological burden of debtIt really depends on your personal strategy and where you want to place your risk. 

@Anthony ThompsonHi,-I estimated 3k for any unexpected repairs that were not accounted for.

And some unexpected costs (e.g. had to replace a lot of doors I didn't think about).

There are always unexpected delays.

The only reason I say this is because even if you base your profit based on the MOST conservative numbers, there are always some sort of unexpected incidents that will arise throughout the process, and there needs to be some sort of reserve capital set aside for that.

Real estate is risky (despite what you might hear) There are lots of hidden and unexpected costs.

@Nick Rutkowski in our contractor biz we provide an estimate with a few thousand for unexpected expenses.

Still things come up that are unexpected but at least you're just focusing on the surprises at that point rather than the whole process.