As ni doms, they seem to be the strongest in weeding out irrelevant data and getting a flash of the highest probability. So at the very beginning, they seem to have a birds eye view of the best route and strategy. They then utilize their creative function, Te, within this ni "knowing" to support each of their claims with concrete, externally agreed upon, application.
When I enter a debate, especially one "just for fun" that isn't tied to any real outcomes, I can see the whole discussion space almost like a map. I can see what roadblocks can be put in place depending on which way the discussion goes. I can steer it one way or another, or just let the other person choose the path, then implement whatever argument corresponds to that. When arguing about real plans and actions, though, I won't do this, preferring the shortest path to the end goal.
INTJs handle the things quite logically, but the reason why a premise exists for an INTJ is entirely without logic whatsoever. Its deeply personal for them, often nearly impossible for them to handle with formal logic or to validate externally.
In short, the INTJ are logical about selected parts of things they care about. About the other parts, their arguments seems to be a big fat "don't look that way, that's not the part of the argument I want you to see."
Essentially correct. We don't generally resort to formal logic, and our focus on the end goal does lead us to ignore (i.e. not waste time on) questions that are beside the point. (Just had such a discussion with my INTP tonight.)
Seeking depth and breadth of knowledge is one way of putting it- I call it an unhealthy obsessive disorder that can be a gateway to addiction in general.
It also depends on the context of the debates I think. Whether or not they're for problem solving, recreation, or expressing emotion. I think all T types use debate to express emotion more than they realize.
That research is unhealthy only if it interferes with getting things done rather than supporting it. You are right about context - that is critical. I will debate a practical matter much differently than some hypothetical situation or moral question just for discussion's sake. Who "wins" the first will play out in the real world. Who "wins" the second - well, usually no one really does. I consider it a win if both parties have a good time and learn something new.
If the problem is telling people what they want to hear then Ni would be a pretty good tool, but if the problem is trying to figure out how to physically put a square peg in a round hole it's just not a tool that works. I've seen INTJs attempt home repair or installation projects, and it's just pure agonizing facepalm. Mostly, as with anyone, it's largely due to that asshole inferior function sabotaging everything- making them put the inconsequential details before their priority, and bogging down the process with distracting unpleasantries.
You have made similar assertions before, which always seem at odds with the INTJs I know IRL, including myself. I have no problem with home repairs or installations, whether I figure out what to do from instructions provided, looking it up online, making up my own method, or some combination thereof.
The stereotype that INTJs are good at debate is a terrible lie and should be abolished.
By all means. Everyone should think we are terrible debaters. We don't know what we are talking about, can't hold our own in a discussion, are real pushovers when it comes to arguing. Piece of cake.