Because the numbers are so far from making any sort of sense all these listings have just been sitting.

I think initially it makes sense to find properties that already have finished basements, in-law suites, etc. as converting those spaces to ADUs will be inexpensive and create a significant amount of rental income ($2,000/month+ in most areas close to the city).

Finally from a purely from a cash outlay prospective short term, you could rent a house with roommates and your payment would still probably be Lower than house hacking because rates are so high, over the long period 5-10 years obviously it would cheaper ti buy, hope that makes sense 

Some people are more disturbed by that than others (even if they have nothing to hide) - and following you around may give them a greater sense of control and therefore comfort.

I will plug it all in and see if it makes sense.

Unless you have some ridiculous deal and need funds to close it now, then it makes sense to refinance in 3.5 months.

It can eat into your cash flow, but if you're earning high income from your W-2 job (I assume you are if you're buying in all cash), it makes more sense to use your time making more income versus managing maintenance requests as you scale. 

It definitely makes more sense to do hard money if you want to make the most out of the deal,

Congratulations on the duplex -My investor clients have acquired several multi-family investment properties locally in the market I operate in Northwest Indiana - Figure out your personal investment objective for the next 4 years and align yourself with the next property that make sense in this current market environment-

By doing this, you’ll avoid any surprises down the road and ensure the deal still makes sense for you financially.