How should I flag the above question if I believe it to be nothing more than trolling, and I desire to see this forum avoid falling into a never-ending troll spiral? What would be most effective?
Generally, it's most helpful to just cast delete votes - this site has a pretty active community of users with 10k+ reputation (and 20k+ which allows "quick" delete votes immediately once a question is closed).
Questions like that which can be deleted via community vote should be done so as a first resort. Moderators will delete content (I just cast the 3rd delete vote on the question you linked) but will prefer to not be the only people deleting content.
Ultimately, the community sets the "tone" here. While we moderators are most certainly opinionated and have our desires for where the community should go, generally we're not going to try to mandate policy on the "squishier" subjects.
From a practical perspective, what that means is I am much more hesitant to delete a question if it has no delete votes. I try to use my votes sparingly - I see casting a third delete vote as more my "user" hat but casting the first (and last) as more the moderator hat. I prefer to be my "user" hat.
This is true in terms of the flags too. Flagging a question asking for it to be deleted will probably be declined, but flagging it saying "this user appears to be blatantly trolling" when there is at least one delete vote on it is far more actionable.