My plan would then be to diversify by partnering with my mother-in-law on fix-and-flip projects for a year or two, which would increase liquidity.

In Oregon you can kick out who ever is living there unless the federal law regarding arms length leases comes to play..

Are there some local laws I am unaware of or why is this happening?

Its hotel law not landlord law. 

I found out in my jurisdiction that medium-term rentals are classified as long-term rentals and therefore have different laws.

The state doesn’t have rent control laws, but landlords are prohibited from collecting more than one month’s rent for security deposits.

So I'm guessing it might depend on your state laws and personal situation. and make sure you know of any sticky items that would eliminate the protection you get from the LLC.

My Brother in law has a company that does this and hand full of realtors have him on speed dial 90% is pipe burst done in a few hours 7 to 8k per..

Preliminary experience stemming from construction as a young adult to gaining my degree in law.

Please note that I have 25 years of experience renting out apartments and houses in three other states, but I’ve never done so in MA, so I don’t have experience with local MA laws or vendor expenses.