I would recommend shopping around, especially with a local mortgage broker.

I want to know is it more cost effective or easier to purchase the property alone and put it in a mortgage in our name or purchase the LLC from him that holds the property within it.

The tax benefits refer to the tax deductions from mortgage interest and property tax.The returns mainly rely on appreciation, and the cash flow only improves in the last few years, also depending on securing the 5% refinance rate.I've learned a lot from this forum, but as I start to operate on my own, I'm still not completely confident.

But this was an awesome opportunity for me because this is my first living situation where I will be on my own (and getting used to paying a rent/mortgage) but this will put my overall mortgage on a 400k house at roughly $2000 a month for the first year!

and soon realized that there was no aviable apartments in or around the same neighborhood for the price that they were looking for. if they wanted cheaper rent?

Why pay rent when your landlord gives you free housing, free maintenance team, free mortgage, free electricity, free water, free trash?

Most mortgage companies will not call loan due if payments are current but you do run that risk and need to be prepared to payoff or refi at a moments notice.

Quote from @Edgar Duarte: hi allI would love to get some perspective from your expertise, we have a property that we would have to sell in 2025 to avoid paying taxes on the capital gains, we believe we rcan sell it for $700K and get an equity of almost $500K after paying the mortgage balance, if we invest all of it option in index funds at 7% rate (standard com growth calculator), or in more rental properties as we are all here for, I can get the equity of around $900K.option B would be keep paying the house at 2.3% int rate while we have it in AirBnB and maybe sell it in 10 years for $900K, knowing that we would be paying taxes but it is not that bad still. or we can 1031 at that point?

So are you saying the Mortgage One deal would be the way to go? 

Pay the mortgage.