Are attacking hyper skills mainly designed for bossing only?

You got them all down from what I see.
DB's asura is not a keydown, but it's similar to IL's hyper or Blade Dancing/Ultimate Drive. You can move with the skill, but you cannot use other skills at the same time (besides FJ). I have no idea why it's got its own buff icon, but I love that because you can extend its duration and lower its cooldown

I don't understand what you mean by them being made for bossing though. Some are, but most are just great mobbing/high damage skills which are equally useful in mobbing high HP monsters and bossing.