Hi, thanks for the comment.
1- The Xapo Bank do not lend the dollars to other people. They have 4.1% interest because they invest the dollars on US treasuries bonds of 3 months. They pay like 80% of the interest to Xapo user and take 20% to them.
2- I read in many parts that Gibraltar is considered a stable place to banks.
3- I think everything that envolve fiat money has risks. But I consider Xapo a serious company.