The issue is murky because, despite the purported exactness of the term, "Aedra" is still subject to interpretation, and how it is ultimately used may even be subjective. Aedra and Daedra says that "ancestor" is usually the definition of the term, implying that there are other definitions with different connotations attached. It's the elven word for "ancestor", but does that mean it should be construed as "elven ancestor", or could anyone refer to their ancestors as the Aedra? The book isn't even really clear on its face how the Dunmer typically understand the term despite explicitly mentioning them.

If Aedra is defined as "creators of the Mundus" (which is, after all, how the elves view their ancestors), then Talos could be understood to be an Aedra. If it's defined as anyone's ancestor, then the world of men might consider him an Aedra. If it's "elven ancestor", then probably not.

Very true. Semantic is an important and difficult problem. A word has its sense and reference, and sense has internal part and external part. But it's up to us, the users of this language, to decide the extent of its meaning. We could let things stay murky of course. There is nothing wrong about that. But if and when we have to draw the line, and use these two terms "aedra" and "daedra" to define all the gods, then I think Talos would have to be an Aedra. He could be a demon though, but no Daedra.

What's more powerful? Wind or rain?

wind

I'm of the mind to disagree, they're the Living Gods of Morrowind after all. I'd say ALMSIVI and Dagoth are in a unique niche of their own, completely distinguishable from both the Daedra and other divines. As for Mannimacro and Talos, their policy of Not-Doing-Much is comparable to the others, but its hard to pin exactly what they are. Depends on the context on how we're referring to Aedra more often then not, since the term isn't exactly common in the game itself. Though we've only been in human territories for the past two games that prefer Divine over a Merrish term, so that could change.

Where would Numidium be on that scaling? All things considered, I'd say Numidium falls into the same category as ALMSIVI and Dagoth.

Also, as for Mannimarco has it been determined what was going on with him in Oblivion? Was it just a imposter using the name for his own ends or did we really foil the King of Worms?

Depends. You can still find a small alcove of mages in Skyrim praying to Mannimacro, but there's nothing signifying that its a significant event unto itself.

The way I see it is this. Mannimarco the Mortal and Mannimarco the God were split apart during the events of Daggerfall, where he failed his ascension in one timeline and succeeded in another. The end of the Dragon Break couldn't reconcile these two events from one another, and thus both are still at large. Whether or not the mortal half even recognizes himself in the Necromancers moon is another story. Or, as you said, its an impostor rendering the whole thing moot. It wouldn't surprise me either way.

As for the Numidium, I always saw it as the vehicle to godhood rather then the end result of an attempt to create one. Mannimarco and (in my opinion at least) possibly Septim both wound up using it to achieve their own ends, and the Dwemer were certainly going to go further with it then create one singular entity if I'm not mistaken.

I'm a Dunmer, to us Daedra means "Our stronger, BETTER ancestors" and I consider that to be true.

Trick question. Both Aedra and Deadra depend on Akatosh to keep time going so they can keep track of who they are. So in a sense if it wasn't for the Aedra Akatosh, neither Aedra or Deadra would properly exist.

That said, I think it says something that the key difference between the Aedra and Deadra that Lorkan wasn't able to convince/force the Deadra to help him make Nirn. Why he wasn't successful in doing so is up for debate. What it's at least partially linked to it though is that the Deadra (the Princes at least) saw the Tower the same as Lorkan did and didn't understand what it was like Lorkan did.