Second point: That's only for legendary member and I'm not even near it.
You are correct but due your trust rating, maybe you stand a chance to get it from TF.
Without a signed message, seems too hard to see this filled from any other...

I'll fill this loan if you sign a message and give your account up for collateral with a trusted escrow
He already answer that he can't sign a message from any of his addresses. Please read before you post.
I don't think signing bitcoin address is the only way to prove ownership to an account. There can be other ways too, not sure what they can be
Just found an address that will support my claim on this account. Although never used to send or receive payments.