I don't keep any CEs sealed, unless it's one I've just been too busy to open/never got round to, or if it's an empty preorder bonus steelbook.
When opening, I carefully tear open cellophane and bin it. If any stickers (such as ratings or "___ demo inside") are on the cellophane, I carefully cut round them and keep them inside the CE/steelbook.
If sealed with tape, I carefully cut, if sealed with circle stickers, I peel (unless REALLY stuck down, then I'll cut).
I have a look through everything in the CE, and then if there is a statue inside that I want to display, I will take that out and display it alongside the outerbox - unless the outerbox is massive, then it goes away into storage in one of my wardrobes (if they go into the wardrobe, I bag them first to protect from dust/damage). Games stay inside the CE box until in use, if frequently used, they usually end up in my standard games shelf, but I always know which CE they've come from.
I have lots of shelves (albeit not enough to house all of my collection), so I have some shelves which are for specific franchises, and some which are just general shelves. I don't collect for one specific franchise, so a lot of my collection is mix and match, but I think it fits well
xx