There are many features that tend to limit players' originality or doesn't reflect players' personal preferences. This thread is to point out areas where it would be nice to see more options available than what we have. Feel free to add more, just typing in what I remember for now. Here are some popular, simple, and easy-to-implement suggestions:
create more deck name options
create more player names for boys and girls
create more pet names
make Menu Chat remember your favorite phrases forever
Additionally, here are some other popular ideas, although they will require more effort:
add a fully customizable MS Paint-style color palette for the dye shop
revise Team-Up so you can put limits on schools, levels, team roles, and dungeon goals
create a "turn off recommendations" checkbox option in the Crowns Shop