So there are no plans to have any kind of dedicated, searchable deck depository, this would purely be for the text decklists that people are already posting, making them look a little nicer. Something like a TCDecks integration would be an entirely different set of work that I'm not considering at this time
I'm not too worried about the fun names that people register decks with. There's nothing stopping people from writing the name "Peazystorm" above a decklist now. I agree that "designer" could add drama, but I think there's value to being able to call out "this is a list I made for this post" vs "this is a list played by X in tournament Y", a generic "playerName" field would do that.
Technologically, logic-free tags like "deckname"/"playername" don't add any complexity to the feature, so don't worry about that
I agree that being able to seperate cards by category makes a decklist easier to read. I think maybe the best way to handle this is allowing users to mark their own fields - some players won't, but we wouldn't be any worse off than we are now. Any plan involving sorting cards by type would involve making API calls to external sites to lookup card type and then sort, and a huge amount more dev time ... and we're talking vintage which means sometimes artifacts are mana and sometimes lands aren't - I think it's better to let players organize things the way they want to. (I'm still open to something more complex, though, if that's what people want)