Testing confirms that packages labeled "dependency" are those which are installed only because they are dependencies of other packages you have installed.
The package manager actually won't let you uninstall a dependency (as doing so would break the package that requires it). Similarly, uninstalling an "installed" package which is also a dependency of ...
I can't tell you what it means (I can guess, but you'll probably get a good answer here).
But I can tell you how to ask Emacs about it, in case you don't already know. Usually the Emacs doc provides such info (it should).
C-h f list-packages gives you a brief description of the command.
C-h r puts you in the Emacs manual. There, i list-packages takes you ...
I have not found a builtin way to accomplish this "easily", so I wrote the following two functions which can manually be invoked to change the status of all todo states in a subtree to CANCELLED and back. You can use undo right after cancelling to reset it but this won't work some days later, therefore the uncancel-function.
IMPORTANT: This includes ALL ...
use-package is a macro around require. Macros are expanded before code execution. The purpose of a macro is to create syntactic sugar to make code easier to read, understand, and maintain. Your different alternatives have minimal effect to the execution time. In the end, it is a personal choice which one you prefer.
I use mostly the :after key for terseness, ...
It is actually explained in the docs that it is possible to simply override the enforcement of todo dependencies by using the C-c C-t command with triple prefix argument: C-u C-u C-u.
Also, there is no need to set all the subtasks individually to CANCELED state, as the archive-tag archives the entire subtree, which removes all the subtasks from the agenda.
Have you seen Karl's article on org-depend?
I think that I'd try to use org-gantt and taskjuggler to create an overview for more complicated task blockades
Maybe that's a bit too much, where I'd try to graph with dotty maybe.