If you were willing to spend hundreds of dollars, why not hire a lawyer to proxy your application? With a POA the attorney should be able to sign documents on your behalf.
I don't think there's anything there that doesn't boil down to providing sufficient identity documents. Worst case making him spend a fortune with a notary public to get copies of various documents notarised and possibly having apostille's issued.
His bigger problem is likely to be US reporting requirements as I've mentioned elsewhere, that makes it very unattractive for non-US banks to handle smaller US clients.
