In its current form, Katana on a rogue is really uninteresting. The idea of firing the skill when an exclamation mark appears above the head could be even interesting, but unfortunately it does not work. Large groups of mobs crowd confusion on contact dps this form will not pass, very often it is hard to notice this exclamation. Please change it in some meaningful way.
Next thing you are adding new weapons like Pistol, Katana, Guitars, Spear, etc. which are practically not used at all and no one is running with it because the connections on which they can be used are simply too weak. The variety of weapons is nice in my opinion, but it would be nice if each of them was really useful.