Water through Intake Manifolds

I have never seen a reason for either a heat crossover or water heating an intake manifold, other than emissions or maybe, and it's a big maybe, fuel economy.

Your distribution issues are an intake manifold design issue. I block the heat off on everything I can. Or, better yet, I use an intake manifold that doesn't have a heat cross over to begin with.

And I drive my junk year round, always have and never have I had a carb icing issue. Ever.

Also note you WILL need to change the tune up when you block off the heat. To the point most likely you will need to have staggered jetting.