You can budget for any initial repairs required and determine what deferred maintenance requirements will look like.  

The price your house will sell for isn't a magical number that only the best realtor in town can get to, but it's determined by careful CMA.

That will help you determine the numbers part of the deal when it comes to expenses.Second, when house-hacking a duplex, the goal isn't cashflow or living there for free, it's reducing your monthly obligation to the mortgage.

This is key to picking the right properties to invest in.

@David OlsonI am in no way an expert at this but I believe when you are making a cash purchase the main team players are:Attorneys, Title Company, Inspector and Appraiser (occasionally)Attorneys: Using legalese to get the purchase contract in writing Title Company: Perform due diligence to make sure there are no liens against the propertyInspector: You already covered thatAppraiser: To determine the price of the property at its current state and after repair value.

If I renew with the current tenants, I'm saving the property owner the cost of turn over and placing a new tenantThere are many different fee structures that PM companies use, definitely look at all the areas you're being charged to determine if they are a good long term fit for you.

Pre-qualify the OfferHas anyone heard of running prospective buyers through a seller's choice of a pre-determined bank to get a solid review of their credit?

You'll pick it up with practice.

Study your market to determine what the higher demand is and act accordingly.

All I can do is postulate various scenarios about what might happen and then determine an appropriate all-weather strategy.(1) If the market continues to take the escalator up, what would I do?