Some smart water monitors can track usage, send notifications to your phone, and you can pair them with a smart valve on the main to kill water to the whole house when they detect a leak.

The easy solution is using a conventional loan with a low down payment.  

I have seen and recommended to most of my investors that solution which help you reduce the stress, without the needs to go to a property management solution. 

For developers & investors in North America, there is a new route to market leveraging on proactive product based offsite construction solution.

These loans are structured with a combination of a first mortgage from a conventional lender (typically covering 50% of the project costs), a second mortgage from a Certified Development Company (CDC) backed by the SBA (covering 40% of the costs), and a down payment from the borrower (typically 10%).Bridge Loans: Bridge loans are short-term financing solutions used to "bridge" the gap between the purchase of a new property and the sale of an existing property or the availability of permanent financing.

When its important, you'll find the solution that works best for you.  

I know with private $ we'd have a higher rate but was hoping it'd be a short term solution if we could refi into regular 30y mortgage

Recently purchased a 4000 square foot commercial office building in Canton OhioLooking for an inexpensive insurance solution. 

security system and ongoing monitoring.

Most small balance multi family complexes will not yield a 8%+ CAP in today's rate environment..unless they will consider seller financing..with 30% down there should be some options for creative finance solution.