Silicone has been "banned" from our boat!

Except for one and ONLY one place: Our Beckson portlights 'cuz Beckson says to use it! Really. I used to use it all over, but after reading lots of material and Maine Sail's excellent contributions, I find it useless, and impossible to remove.
Butyl tape, the nice stuff offered by Maine Sail, is great for rebedding everything that needs to be bedded. I used it for my saloon hatch recently, two of six chainplates and stanchions galore.
5200 is great for hull to deck joints, and one other thing that I think Rich H brought up, but that's about all.