[Q] Can an EB-5 investor use funds unrelated to the EB-5 investment to purchase insurance from a third party (e.g., Lloyd’s of London) in which insurance proceeds would be paid to the investor if the commercial enterprise fails to repay the investor? Assume the third party is unrelated to the commercial enterprise or a regional center.

Let me quote USCIS' answer to this particular question in its entirety, because this issue opens up interesting stuff.

Yes, as long as the alien investor’s capital is “at risk”, and the indemnity policy does not constitute a redemption agreement or a guaranteed buy-back arrangement for the alien investor’s investment in the commercial enterprise. A determination as to whether a specific indemnity policy is contrary to the statutory and regulatory requirements has to be made on a case-by-case basis.