Little question about this, cause I have been experimenting with this and and been reading a lot about it too and how to work with it.

Is it possible to add costumhooks? So that you can add hooks where there aren't and tag them so you always know they are relative to your hack and so you can afterwards reuse them for addons or so?

Or am I totally off the subject and should get my brains fixed with an axe?

As far as I know this is NOT possible. You'll have to edit the php files to insert your code there. But you CAN request hooks @ vbulletin.com