If I invested 100K today, they are currently providing anywhere from 60 to 72% passive tax deductions due to cost segregation, depreciation, etc. 

Sure don't do the renovation, I only do renovations that project a return of 2x the cost of the renovation.

There are also additional costs of operating and maintaining an LLC, like separate bank accounts, annual report filings, tax filings, etc.2.

Since you know what you need to buy it at and an average rehab cost, I would say $50-70k for a cosmetic flip, set the ARV based on the sample you choose and doing comps and ask them if they would invest in a deal similar to this. 

To offset costs, I’m planning to buy a duplex and pursue a house-hacking strategy:1.Rent out one unit as a long-term rental.2.Live in the other unit and rent out the bedrooms as short-term rentals (STRs) through a furnished rental approach.Before diving in, I have a couple of questions:1.Can I use a property for both short-term and long-term rentals?

Their cost basis is about $33k, the agreed upon purchase price is $250K and the expected appraisal might be around $350k-$400k. 

The process from start to finish would take four months and cost ~200k to build, with comps in the area around 355k-lender man said, refinancing would take six months as most lenders wont refinance a property unless its been built for six months, affecting the strategy to get paid out from refinancing quicker and closing out on construction loan-The property would not appraise at comps value, but at the cost it took to build, affecting getting paid out from the refinance.

Is it common for developers to use subsidies to cover 100% of the construction costs without needing to obtaining debt or raising equity?

Id keep looking if it was not an approved short sale ( even an approved short sale takes a very very long time and theres no guarantee that you will even close on the house after months of waiting). q1)There are plenty of non traditional lenders that could offer you construction financing if the numbers make sense but it will cost you with points and a higher rate.

The property offered a balanced investment opportunity—enough to significantly enhance its value through renovations, yet manageable in scope and cost.