It can be scary when you think about the larger numbers, but just keep in mind, they're just numbers.

Buy one larger deal at $1.6 mil with ????

At this point in time, I can't justify investing there when I can deploy slightly larger amounts of capital at a comparable price to rent ratio in parts of the SF Bay Area. 

Business products that that scale to larger amounts are Buildium, Appfolio and ManageCasa especially for someone with less 50 units, since the entry price is pretty low and they include maintenance management.

Even in my market it'll differ on size:  Airbnb comprises most of the smaller sized units but it flips to vrbo as unit size gets larger.

However, I read setting a max price of $250 for maintenance issues would allow smaller requests to be taken care of and larger jobs brought to your attention.

When you get into larger (5+ units), mixed use, renovation, vacant buildings, etc. they will need to access commercial policies.  

The statistical likelihood of these problems happening when you have 10 properties is no greater on a per property basis, but you have a larger risk pool.

The property is 1.4 acres and the pond seems to take up about 20% of it, definitely larger than the house.Things to consider / watch out for?

The IRS requires this on any larger capital expenditure so they can avoid large tax losses in early years.