The primary reason a lot of people move on to bigger deals (80 units plus), is that it's possible to own larger properties in markets that make economic sense but may be far from where you live. 80 Units seems to be the target so you can hire your own full-time property manager and maintenance person, versus relying on local property managers to manage smaller multi-family properties on your behalf.

Profitability varies based on location, seasonality, additional costs, occupancy rates, and reality checks.

I suspect the new title examiner has found something in the chain of title or the execution and notarization of your deed that makes them unwilling to rely on it to issue your buyer a policy without exception for the concern(s). 

I've been relegated to rely on private money and owner financing.

A few deals fell through because of varies reasons, but ultimately we had tons of action on the houses and eventually found the perfect buyer.

I simply rely on Airbnb and VRBO (although the vast majority of my bookings come via Airbnb).I have a great cleaner and I'll have a handyman, plumber, etc. come to the house when needed for those things. 

However, the specifics can vary by lender.DSCR's are designed to accommodate various investment scenarios, so they can be quite flexible with terms and will typically have slightly higher interest rates compared to traditional loans and might require a larger down payment. 

The cash flow and equity will make you rich in the future and you need other sources of income in those first years so you aren't relying on the cash flow to live off in those early years. 

Deductibles vary by carrier, state, property. 

As I said, this varies from state to state.