I still think the honey is gonna give you a hell of a time getting it to dissolve, assuming you are storing cold. Even with a good shaking, it will likely still be fairly clumped and settled in a cold keg, all around your dip tube. It may dissolve if you give it enough time and flip the keg periodically, but if it is settled and you hook it up and pull a pint that takes half your honey out, you spent those weeks waiting for no benefit. I'd say get it dissolved in a syrup, add it and shake. Should mix more readily throughout.
Your idea was excellent. I vented the keg and let it warm up. Vented again. I dissolved the honey (with sorbate) in just enough warm water to make a thin syrup. I stirred vigoursly, re-sealed the keg, chilled and re-carbonated. Tastes better than I could have imagined. A whole new beer. Thanks again for your input!