I'll let others chime in on their experiences, but from a motivational perspective, I think attending live events and getting the "conference high" is something that only happens through in-person connections and being in the same room with investors who are eagerly pursuing their real estate/financial goals. 

All these areas have started gentrification path and have a lot of room to continue growing. 

Depending on the flooring specs you *might* be out of luck because a lot of LVP/laminate type flooring specifies on the install that straight runs will be no longer than X number of feet and room changes will be installed with a transition.

If you house hack a single family residence by renting out  a room or two then you would have no property tax but if you buy a duplex you might have to pro-rate the property tax.  

I can's imagine a situation where all 4 tenants have elected to hand wash their clothes and use the dryer (there is no utility sink in the laundry room).Can you think of any reasons why the dryer would be used that much more/washer used that much less?...

Now I'm renting one room, Airbnb'ing one, and using the third.

(Especially a 2-4 unit.)Do they have friends/relatives/co-workers that would rent rooms from them if they bought a property to show more income?

Live in it and rent rooms or units out.

For example, I have a subject property that has 1682 SF on the main floor and 810 SF of finished basement (the majority of which is about 8 feet in height with the exception of some bulkheads to hide the mechanicals) and 271 of semi-finished basement that is a utility room basically (washer/dryer, freezer, hot water heater, furnace, some storage).

Depending on the market, A game room can give you a similar ROI with much less liability.