We also require that we be added to the contractor's insurance as Additionally Insured, so we're covered if they cause damage or liability issue.3) If the property is occupied:- One of our people MUST accompany their person (and we charge for this). --- We were sued many years ago, along with the owner, because tenant claimed owner's contractor sexually assaulted them!

The issue is cost.

He makes sure we maximize all deductions and have no issues.

I have had no issues finding renters for our units and have have minimal turnover.

It provides an opportunity to see what's happening in the units.You still have the ability to evict for lease violations, but your less likely to face non-payment issues. 

Why is this an issue?

We manage a property that was having drain field issues for awhile, got estimates and had the owner approve one of the vendors.

I've asked my clients a similar question and have developed tools for them to minimize this, but I find there are a few different types of clients.Manager managed - these folks have no issues as they simply upload their year end statement from their property manager, their 1098 mortgage statement and any other one-off expenses they may have paid for outside of the management company. 

Leverage will not change the effort or risk in the areas OP identified.  

The issue I had was that most lenders required a certain number of completed flips done under a LLC.