Question 2. Where can I confirm the existence of International Orphan Aid (IOA)?

The Internal Revenue Service offers a Charitable Organizations Select Check system to verify eligibility status using our EIN #27-2403326 Exempt-Organizations-Select-Check

Another public source is http://www.charitynavigator.org. At Charity Navigator anyone can search to see basic financial and tax reports of public charities. However, they only highlight charities with more than one hundred thousand dollars in revenue so you will need to do an extended search for International Orphan Aid, Inc.