Thats why i said to come over here and do all the papers ( notarization ) thats the trust. Who want to invest is welcome to do all the investment talks and legally.
Op, if you were US citizen would you come to some foreign country to finalize business with a stranger after brief introduction and assurance that the deal will be legit?
I would rather find another exchange supporting US citizens, which we have plenty around BTW (Coinbase, Gemini, Kraken, BitStamp, Wall of Coins) and be fine with that.
Or, perhaps you are offering something more than simple proxy access to bitfinex?