Name: Joker (this journal)
Can Haruhi bug your character? Yep
Can Haruhi make weird powers-related incidents happen around them? If she wants! Just ask first before big things, as you said.
What power-related things do you not want to have happen to your character? I don't rule anything out.
Other things Haruhi can't do to your character (grabbing by force, blackmail)? Again, nothing is ruled out.
Anything else? Nope!