Here's some generic guidance.Software is a common question on BiggerPockets.

Does the 60% the condo-hotel takes include the HOA fees or utilities or replacement of furniture/repairs to the unit like plumbing or stuff like towels and sheets etc?

I have $100k in cash to utilize to buy a long term rental property.

Seeing a $100-300 increase on a single unit is common in NJ.  

A standalone ADU is almost always going to cost more than doing an addition, so the value added or cash flow increases will have to justify each.I work with a team of investors who will buy SFR homes then build a new ADU on the lot and add a separate drive way and meters for utilities in North Texas. 

House hacking is not only a phenomenal move for investors starting out, but it's a common strategy in expensive markets like Boston.

Since your friend covers utilities, this offsets some of your cost.

A person living independently or a group of persons living as a single household unit using housekeeping facilities in common, but not to include more than three persons who are unrelated by blood, marriage, adoption, or foster-child status, or are not Life Partners.Splitting the building into two 4 bedroom units is not allowed. 

However, if you want to flip you may be able to make irregular chunks of income quicker that can make up the difference.Which leads me to the utilization of your equity.

So as long as your insurance, property taxes, property management, utilities maintenance, repairs, vacancy, and capex come to $4/mo or less you’ll be fine.