Since you're already buying in GA, you could connect with turnkey providers local to your existing portfolio.

As the calls rolled in, we scheduled resident viewings with very little pre-screening activity.

PMI is so cheap that you could put that extra 15-20% into a US treasury bond and have more than enough to cover PMI. 

So, pre-purchase I use this estimate and then once I have the deal under contract I can use the time between then and closing to firm my plans up.

Would need more details about your plans and goals but generally it is going to be much easier to start with existing real estate rather than dealing with raw land.

Servicing existing residents and leases upon purchase.

My graduate school is pretty cheap and I know that the grad plus loans that I can pull will be able to cover a mortgage payment and my tuition.

Note: if the cashflow comes out negative, you technically aren't "losing", because your tenant is at least partially covering your biggest monthly expense which is housing... 

Last 4 years have been an anomaly so weight the pre 2019 data more than 2020-2024.

You'll have a bit of a vacancy, but if you can get the property marketed and turned over quickly, it will be minimal.Do a pre-move out walk through so you have an idea of what you need to do and if you need to hire anyone after they move out.