People say RE investing is ONLY about numbers, but in reality that's just not accurate in my opinion. 

@Vinay M.Recommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder, etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

Exactly how accurate is there forecasting track record?

The way they aggregate rents is not very accurate.

If you can consistently source good deals, your numbers are accurate, and you're straightforward with people, you're absolutely golden. 

They told me they applied and are saying they need a tenancy agreement or lease which doesn't seem accurate.

This ensures you have accurate information at your fingertips.

Both are free, and for my market (Myrtle Beach) are more accurate than AirDNA.

This property should cashflow anywhere from $200-800 (net) depending on what I can rent it for/how accurate the comps I've found are.

At this stage, I hope to have enough experience, and the network to be able to accurately estimate total expenses, allowing me to move towards bigger projects with bigger potential gains.Any advice on ways I can move forward with my goals?