Honestly looking at your situation I'm not sure I would recommend you do the taxes yourself,  change of accounting method (F 3115) isn't easy for someone that hadn't done them before these online software companies make things seem easier than what they are, they are good for less complex situations. 

You state, "your lender" - I admire the loyalty but also would recommend you get a minimum of 3 quotes (at least two from mortgage brokers).

Who are great property managers in Atlanta you would recommend for my circumstance?  

I'd recommend an investor be liquid 75k - 100k to make sure they can get this done and have a cushion, cause as we know you always need a cushion.

But I highly recommend reading "Who Not How".

I am starting my first househacking deal this year and I will Segway that into my second deal by end of 2025.
I would love to hear all you experts and pros with experience to tell your story. If you are in the Seattle...

Any tips, warnings, or real-life lessons are welcome! 

I recommend you budget 5% of the gross rent (for the whole place, even what the rent would be if you were living in it as a tenant) for repairs and 5% for capital expenditures.

I think I have all of my ducks in a row but I want to hear from other investors who are interested in this model.Any tips?

If you don't care about making money as a rental, that is my recommendation.