Fewer accounts will help tools like mint.come or pocketsmith.com work well if you don't want a full blown system.  

Additionally, being able to detail out each unit of the rentals (ours are MF) and even attach leases and other documents is key.Lastly, is you take your time to split up the closing cost wire transfer in the system, you can keep the closing costs separate (Capital) separate from other transfers (Escrow, rent, etc.) and therefore keep your cashflow reporting accurate. 

By using a data-driven approach to all our property selection, staging, and pricing and occupancy metrics, along with an interview process with the owners, we have developed a great system for aligning with the right owners.

I'm redoing the HVAC system in a top/ down duplex.

What about the electrical system?

I have a contract with an HVAC service to clean/check each HVAC system twice a year (typically at the beginning of both hot and cold weather); they also make certain those filters I leave tenants actually leave the box and end up in the return during these checks.Some Property Managers do monthly check ups: these tend to be done more in apartment complexes than SFH. 

You are smart and could build a team/system for any so it's choosing the one.

Are the mechanical system in stable condition?

Unfortunately, this is not  a home that I would expect to appreciate at all and its not in the best of areas (I've seen many people grading areas on this site, I'm not super familiar with the scoring system but I'd call this a D area). 

*markets usually don't just crash because they've gone up, there is usually a catalyst like some sort of stressor that is added to the system.