After we made our offer and showed proof of funds, we were then sent another document to sign that was titled ‘21 Day Marketing Period Offer Form’.

As far as the signing then a trustee typically signs "in their capacity", something like this:Joe Smith as Trustee for the Bill Miller Living TrustEscrow probably would not be concerned with "...that these 3 are the owners of the trust?"

I recently signed a contract on a single family residence that I am going to be adding to my portfolio and have an investor who will be putting up the cash for the down payment. however I will need to gain financing to cover 80% of the purchase price.

Should I let the tenant know from the beginning it will be a short-term rental and possibly sign a 6- or 9-month lease or even month-to-month?

Sometimes occupied properties are listed saying no walk-through at all until a signed official offer has been accepted. 

I've used them for doors before & I see their signs a decent amount.

She mentioned she would vacate the property as stated in our signed lease (her words). 

Sign up in your name/compnay name.

Is it still being done by direct mail, bandit signs, cold calling to get the phone ringing with possible seals?

I'm now looking to partner with someone who will bring their net worth to the table and sign on the loan with me.