I don't think the honey mixed in would be an issue. You just can't give them actual honey because it could contain spores of Clostridium botulinum--which can possibly cause botulism in babies, but isn't harmful to adults. (I checked my copy of What to Expect the First Year for this information). So no worries if the honey is in something and has been cooked.
Also, the "nuts" in the cereal would not worry me unless nuts are way up high on the ingredient list. Lots of things we feed our kids are made or processed in plants with tree nuts or peanuts. In fact, I am sure plain Cheerios are made right alongside the Honey Nut ones.
I agree with Liz's point about the sugar, too. Not that it's terrible, like she said, just probably more sugar at once than Gabe is used to. He might be bouncing off the walls for you!
