I don't do very many of the argent tourney quests, I'm working slowly on a valiants task by killing scourge each day along with my dailies.

Carbonite does highlight the most likely spots to find scourge that count toward the quest in icecrown - not sure about the others since i only did them a little back when I was an aspirant and they were annoying. I seem to recall it highlighted the place to find the kid that started the jousting challenge.

I have noticed that some of the wide-open quests don't highlight anything in carbonite - i.e. the jewelcrafting dailies never highlight anything, but i've used the map notes feature to tag the closest points to dalaran for each of them.