However, how many plots could I fit on 2ac of land without being obnoxiously close but also maximizing the profit potential? 

Ideally, a commute of no longer than 1 hour is what I am shooting for, however I am certainly flexible with that.  

Software-wise, you can combine accounting software like Quickbooks and Some tenant management software but you as you say Appfolio is manual entry but some modern software you won't have to.The important point is that you should find the right fit for your needs.

Seems like a rather small house to fit 6 bedrooms based on the pic.

It's not a fit for everyone but definitely has it's place.

If you do, it may not be ideal to quit your job for the uncertainty of "door knocking".If your goal is to be financially free, and your wife will soon not be working, giving up your income may not be the best course of action, especially with a baby on the way. 

Ideally you refi over the rehab and holding costs.Also, the point of the refi is to reinvest your principle as quickly as possible.

We survived but it wasn't ideal.

Why, I also thought of doing is, partner with real estate agents, say about 3 good ones, who won't drop the ball, remember, you have to have a good reputation and you are still tied to the deal, so make sure to pre-screen the agents your feeding the leads to, and I recommend 2 or 3, because ideally you will be sending loads of deals and sometime you can forget who you send them to etc...And also, I recommend you hit the agents that you are sending leads to and follow up to make sure they are doing what they are supposed to.Hit me up, we can bounce ideas of each other.

I had envisioned having several qualified applicants and choosing the best fit from among them.