Command-up arrow moves up a directory level. Command-down arrow makes a logical choice for moving down a directory level, and since moving down a directory is t

Command-up arrow moves up a directory level. Command-down arrow makes a logical choice for moving down a directory level, and since moving down a directory is the same as opening that directory, it follows command down would also open a file. Whether renaming as “enter” is a good shortcut or not, I think the navigation ones are perfectly reasonable in that if you learn one of them, it’s opposite is easily guessed.