He was an MIT grad in physics and minor in math, his girlfriend was a mathmatician too. Clearly he must be intelligent.
Yes, depending on how hard he worked, properly a bit above average. But really it doesn’t say that much.
I would assume that he would be smart enough to funnel money out to secret untraceable accounts
Why? Those seems more like something a lawyer or economist would know about. As you said he graduated in physics and maths.
But I agree. He should have been smart enough to at least hire someone to help him with that.
I don’t see how any of superman’s powers would improve his ability to cook spicy food, so no.