I HIGHLY suggest you connect with a local expert such as @Josh Green.

Typically, the initial upfront for the rehab is either cash or a high interest loan (hard money or private). 

The main reasin is for a better clearance of liability. with you editing a signed contract, that has a high Probability of letting a tenant be able to void the contract and it actually happening.

Specifically, Texas has some of the highest insurance and property taxes in the nation, but the appreciation makes up for those high costs in the long run.

Costs will seem high relative to the loan amount on these smaller loans, $5-6k in lender fees isn't uncommon. 

Also any tips for automating this as much as possible and how to protect the property financially and property management would be appreciated.I ALMOST understand the rental arbitrage strategy if building a company scaling with say 30 + units and looking for high short term cash flow.  

The plan includes high-yield activities such as property flips and strategic acquisitions to provide liquidity and generate returns.

One fast way to generate cash flow is to invest in high cash flow, low appreciation markets (say several midwest e.g.

Hard money loans offer fast approval and don't risk personal assets but come with high-interest rates and fees, which can be tax-deductible as carrying costs.

The accuracy is surprisingly high and a bit saddening.