Awesome posts, I totally agree with you.
It's not necessarily insulin by itself that's the problem.
If it were, then Agave would be considered "great" because it has a low Glycemic Index.
The reason *why* it has a low Glycemic Index is because it's mainly fructose, which goes straight to your liver, causes all sorts of problems like what you mentioned with Glycation, creating AGEs, insulin resistance, leptin issues, etc.
So if you're going to use sweeteners, my opinion is that you should probably avoid sweeteners with a significant amount of fructose, and opt for Glucose instead.
Even though glucose spikes your insulin, if you're fairly healthy to begin with, a short spike in insulin is probably much better than all the havoc fructose causes under the disguise of "low insulin."