Oh no! Please no!
EE is a lightning fast, full featured great editor. Why do you need such a “feature”? It requires learning, remembering, a shortcut, configuring GUI, etc., etc. Why can’t you select a line and drag it up one line?
Even as it is, there are numerous functions people, including me, are not aware of. These forums are replete with questions about this and that and poor Yutaka has so much work just pointing people in the right direction (meaning the right menus path.)
Please do not burden EE and make it a big footprint, slow monster. We have those and I hate them!
Thumbs down, absolutely, totally!!!