So far I have just been stringing them along asking them to complete or provide documents for me (sellers property disclosure, listing agreement, survey, etc.) and then I pretend I never got them and ask for those same documents again and again and again until they get annoyed and stop replying.

There was a podcast episode within the last 6 months all about legal protections that was pretty good.

Smart buyers understand the value of a Buyer's agent and it certainly is not just to open doors.  95% of my clients are out of state investors purchasing in a market that they do not know nor live in, they count on me to walk the property, access repairs, provide comps and short term rental numbers, arrange and be present for inspections, as well as my ability to assist them getting their short term rental set up for them long distance.  

You said you bought from the turnkey provider.

Considering your equity and cash reserves, exploring alternative financing options like traditional mortgages or partnerships might provide a more balanced approach to acquiring your investment property while mitigating risk.

can definitely get a hard money loan with 30% down on the purchase and the lender providing 100% of construction 

If there is a different set of rules once a tenant stays a month, and there isn't a way to have tenants sign a lease using STR listing platforms, then what protects medium term rental owners?

If you do find one that is good, they will have the tools and knowledge to help protect you and give you 'outs' of the contract that a wholesaler will not.

Because of the protections an LLC offers in this space, I'd simply say my non-expert opinion would be to spend a little extra to make a separate LLC for this new home, for the legal protections & to make your taxes less of a headache for you.

Since I'm young and haven't done this leasing/renting out process before (my house hack roomates have been friends), I'm afraid of onboarding the wrong tenant or drafting up paperwork/leases that doesn't fully protect me as a landlord.