Yes, I’d prefer to have 3 separate lists, with quick access to each one. I guess tabs would allow this, If you have other idea then even better, as long as all element types are not shown in a mixed list.
Yes, entering into a specific type directly would be best as a (possible) click would be saved. Which one to put first I don’t know (for me it’s either Headers or Hooks) but this could be configurable.
In fact, my main wish is to have separate sets of columns for every list – as I said above, I want to be able to show the priority for Hooks and I guess currently it is not shown because Priority is not a common property for all element types. I hope that when you separate them, you will expose more columns for each type.