I have 2 rental properties.The First is in Crestview FL with a long-term military tenant.Cashflows ~ $800 monthly.Mortgage is $180k.

Factor in costs such as:Property taxesInsuranceMaintenance and repairsProperty management feesVacancy periodsLong-Term Strategy:With plans to acquire multiple properties, develop a clear long-term strategy.

Also, how long did it take?

It is not  optimal for long term debt. 

Akron and Canton may cashflow a bit better but I personally don't see as much of long term growth in those cities. 

syndications: very high risk, very high leverage, extremely low liquidity, almost zero control, too long investment too, and mild return compare to ETF/debt investment.There're two ways to make it work for syndication :- you invest as GP (sometimes there's this thing called co-GP fund so it's less risky in theory) ; invest as senior debt or just simply invest to the lender itself, some of these bridge lender (because of the structure) would go up in value when rate go up/down because all risk has been hedged.they make money even if the rate goes higher.

That's the thing, whenever you use a management company to manage your rentals, whether they are long-term or short-term, the fees cut a big chunk of your profits.

-Thinking long term, is this something I could scale to make my primary source of income?

For example look at the zip code you are building in, for a recent new build in columbus that we do since miami is expensive we pulled all these stats: Zip Code Statistics: 43206Housing Units Delivered: 8 Average Sale Price: 642,875Median Sale Price: 505,000Average Price Per Sq Ft: $316.40Average Square Feet: 2172 Sq FtAverage Bedrooms: 3.25Average Bathrooms: 2.75Average Days on Market: 138We design the house around this, around the lot, around the neighborhood, from scratch and try to pick a long term build design that will do well.

Myself as a realtor pre vet its completely legal as long as not based on a protected class such as race etc.