To truly get a good understanding of what cash flow you should expect, you need to study your market. 

Upon graduating, either sell it or maintain it as an income property. 

This will help maintain your timeline.

But deferred maintenance like roof, parking lot, and other big issues should be taken into account.You should probably connect with a tax strategist because it might benefit your business overall to paying higher rent, get higher debt on the property, and have significant writeoffs through a cost segregation study.

Maintain a minimum balance in there (for ex: $500) and the PM will not bug you for any repairs below that price.

Fixing leaks and having a supervisor onsite help me reduce expenses and maintain the building up to code.

I'm not Joe nor do I have his level of experience, but I believe he's referring to the fact that in order to get the most out of all the equity you've gained, you will need to sell and use your $150k to purchase $750K of property while maintaining good cash flow.

However, the Landlord has a duty to mitigate the Landlord's damages by re-letting the property in a reasonable period of time.This is the procedure I follow for early Tenant termination of Lease:First, I maintain a professional, friendly, and empathic relationship with the Tenant throughout the process.

The reason he wants to let it go is because he wants to open up another business in another state and the idea of maintaining a property is just to much of a hassle. 

With BRRRR the reason to pull your equity out is to move on to the next flip while maintaining cash flow and/or sell.