This sounds fun to me, but I'm not sure how the 401k provider handles rehires and eligibility.2) Find a new 401k provider that is more flexible and move everyone over. 

With your budget, you have a fair amount of flexibility within the Atlanta MSA.

The more creative you can get with your living situation while you're young and have tremendous flexibility, the better.

Specifically: speed, flexibility, willingness to lend with higher leverage and for properties that bank would not finance. 

Our generation loves flexibility.

My W2 is extremely flexible.

Similarly, because I plan to buy more, would having a co-borrower give me more flexibility to acquire more property?

Just try to work out a partnership and be as flexible as possible.

For your situation you'll definitely want to pick a brokerage that allows maximal flexibility and autonomy as a part-time agent.My general advice for getting started with real estate is:Define your "why" - what's the underlying motivation/purpose?

The flexibility of being able to invest as much or as little of your gains as makes sense for you has been a good fit for many crypto investors.