I'm under the impression that you cannot invest your 401k with your current employer into real estate, and you cannot roll it over into an IRA until your employment ends.Old 401k's can be rolled over into a SDIRA.As far as the OP is concerned, most 401k plans offer a fund that matches the S&P500 index.

Look into 203k loans to have renovation cost rolled into a loan.Also look into making offers on the 300k properties.

I have received recent rent rolls and see that there are currently 2 tenants that have not paid in full this month.  

You can roll repair cost into a the loan at the low rate instead of having to use a HML.

Things went well and at the end of the deal all the investors wanted to roll their funds into another deal we had going.

So my first action will be to rent out my primary residence, which I have already started the ball rolling on that.

Get a copy of the rent roll--is it believable?

You can request a portion of their tax return to verify the rent roll for the duplex, but that seems highly unnecessary.

My current mortgage balance is $153k; rolling in cost and pulling $20k out I'm looking at a new loan of $182k.  

If with a previous employer then you can roll it over into a self-directed IRA.