Happy to help. If I get other citations on it, I'll add. I tend to lean towards @Anonymous_'s expertise, experience, and advice on the issue personally, but I can see why people might feel differently.
I do wish the IRS more clearly stated/emphasized that if bank interest doesn't come directly from business activities (such as loaning money), then it's not business income.
One note regarding "I don't remember paying a self-employment tax from reporting this on a Schedule C." You did, because when it's included on Schedule C, all net income from Schedule C flows to the SE tax calculation. So if it's on Schedule C, you're paying SE tax on it.
