My last one was my biggest one which included a 1000 sqft extension to an 1100 sqft single-family house.

The biggest take away was my ability to utilize machine learning for this process.

Injuries are the biggest lawsuits, but even those are primarily settled out of court and paid by insurance.

Sounds like your biggest worry is buying something that becomes a hassle. 

Biggest challenge is actually maintenance, finding workers you can trust.

There is too much competition with large scale construction projects who are offering crazy incentives.

Yes In Gods BackYard (YIGBY) is an incentive program many states offer that allows churches and other religious non-profits to develop low-income housing on their land with speed and cost incentives.

My biggest issue is constant issues with VRBO connections.

To all aspiring house hackers and those aiming for a single-family primary to hold it as a long-term rental, what are your biggest frustrations likely keeping you from jumping in the game? 

That's the biggest thing I can think of.