Can Ravalox' Quest Tracker help me hide quests?
 

I installed Ravalox' Quest Tracker and I like it so far.
But I wonder if there is an option to hide certain quests completely, so I dont circle through them when pressing "T". I played around with the console commands but nothing helped.
Is this even possible?

I'm not aware of any "blacklist" inside the quests within Ravalox QuestTracker.
Why don't you just abort the quest if you do not want to see it?
Or write a comment/feature request to the addon developer, maybe he/she implements it.