Is there a financial vehicle where I can park that money and only pay taxes when I make withdrawals? 

Lots of legal opinions here, but most are inaccurate.It is true that, absent an estate planning vehicle (trust, etc.) there needs to be someone with “standing” who is empowered to pass title. 

One of my LTR tenants is a heavy marijuana smoker and the smell is invading my Airbnb.

Its not an always black and white though - DSCR Loans with heavy prepayment penalties can often be equivalent or even somethings better on rate vs. conventional

Similarly, by renting out their house to a STR operator, the landlord receives secure rents rather than taking on the heavy lifting of operating a STR. 

That $15K would have to be enough for either a 3.5% down payment using FHA for example and lean heavy on the seller for a Seller concession (Seller credit) which goes towards closing costs.

An entire blog could be written about the cost of manually driving for dollars… such as paying for gas, depreciation on your vehicle, the cost of your time, etc.In another example, imagine you are virtually driving for dollars in the same target neighborhood and zip code..

Outside sitting furniture is good but if it is on the lawn don't get heavy furniture as the lawn guy has to move it.

Sounds like a very heavy lift for a new investor.

They require unnecessary details, such as pictures and details of the applicants' vehicles, which push potential tenants away.Adding to the frustration, their onboarding team has been incredibly rude and unhelpful.