I have friends in the cabin rental business and it's the same thing.Either you run it yourself and make great margins or to go mainly passive you have to hire someone to do all these things with the properties constantly being rented out and most of the cash flow goes bye,bye with increased operational costs.I view these the same as buying any business where you look at the books and it has an owner operator component to it.Example a Subway sandwich place making 100k profit a year gross.

I think the component you are missing is Leverage. 

Those components will help steer you towards your first deal.  

Compared to an IRA, contributions limits are roughly 10x higher, there is no custodial requirement for the 401k, you can take participant loans, you don't need the additional expense and administration of an LLC to have checkbook control, there is a built in-Roth component, a spouse can also participate, there are additional tax benefits, generally greater privacy, and the plans are often quicker to setup and cost less money over time especially compared to most IRA LLCs.

Landlord references are a critical component of tenant screening but should only be a small part of your overall process, especially if you are just getting bits and pieces of cryptic or seemingly unreliable info from those landlords. 

I did setup a Roth component to the 401(k) and plan on investing more with that arm in the future.  

Compared to an IRA, Solo 401k contributions limits are roughly 10 times higher, there is no custodial requirement for the 401k, you can take participant loans, you don't need the additional expense and administration of an LLC to have checkbook control, there is a built in-Roth component, a spouse can participate in the same plan, there are additional tax benefits (UDFI exemption), and the plans are often quicker to setup and cost less money over time especially compared to most IRA LLCs.

Two components I would start with is ARV and Rehab estimate for any strategy.

You can also couple your self employment(SE) industry experience to get a W2 Salary  job in the same industry and you can use the "base or salary," component after you've worked on the job for 1 paystub or 1 month.  

here is a copy of a blog I did:Hiring a property manager is an important decision, and can be an asset for a property investor, but can also be a detriment if not chosen carefully and without some due diligence.