You would need to pool 3-50 properties that each have a loan of at least $50k against them and the total loan amount would be $300k. 

You can also partner with multiple people in one hard money loan to pool resources together.

There are excusions in the SEC code that identify vehicles for pooling fuds together just in the way you are describing.

Therefore, you're going to have a very small tenant pool.

I had good experience with American Home Warranty, they replaced a microwave and pool pump in one property, helped with $1000 (capped, so read the fine print) for a sewer pipe issue in another, pretty straight forward process both times. paid 4XX per property (respectably had one seller pay it).$75 Service  per call fee and the yearly fee seem ok for the value provided

If the book helps, here's a general guideline to identify the markets:1) your backyard (if feasible)2) places where you like to go3) places where you have friends and family to visit4) place where you'd want to retireOnce you have a list, do your research to narrow down the focus. 

Low maintenance backyard and front yard.

One of the high costs/repairs for their home was the in-ground pool.

I've heard that there are good boards, but the board for the one condo we did buy was extremely wasteful, letting the pool house roof continue to rot, but wanted all units pressure washed for $400 per unit, even though only 1/3 of them actually needed it. 

But it's also not a family tenant pool for this particular deal.