From what I know, it's playable, but it leaves Black with an inferior game when compared to the Alekhine. There really isn't any real refutation to it, but a major difference is that it develops the queen's knight instead of the king's knight, so castling will take a while for Black. I've never played it myself, but I had someone play it for a bit before switching to the Black Knight's Tango, which is 1.d4 Nf6 2.c4 Nc6!?. I personally don't like the looks of either, but from what I've heard the Tango is a perfectly playable weapon, so maybe that will interest you.
Mikenas Defense:Good or bad?
That is the Nimzowitsch Opening. It's not "relatively uncharted territory" at all, people have been investigating it in-depth for decades, it has whole chapters written about it. If you're looking for uncharted territory I suggest looking further than move 1.
Like Owen's, the Grob or the Latvian gambit it's considered "unsound but not a complete joke".

That is the Nimzowitsch Opening. It's not "relatively uncharted territory" at all, people have been investigating it in-depth for decades, it has whole chapters written about it. If you're looking for uncharted territory I suggest looking further than move 1.
Like Owen's, the Grob or the Latvian gambit it's considered "unsound but not a complete joke".
No,it isn't.Nimzovich is 1 e4, Nc6.

That is the Nimzowitsch Opening. It's not "relatively uncharted territory" at all, people have been investigating it in-depth for decades, it has whole chapters written about it. If you're looking for uncharted territory I suggest looking further than move 1.
Like Owen's, the Grob or the Latvian gambit it's considered "unsound but not a complete joke".
That's not the Nimzowitsch at all, which is 1.e4 Nc6, which although has been researched more recently still has a decent amount of unexplored territory, despite several BOOKS (not chapters) about it. Besides, neither the Nimzowitsch nor the Mikenas are unsound, although I would rather have the Nimzowitsch any day. Besides, of your three examples, I would consider only the Owen's Defense fitting that description. The other two, however, ARE a complete joke, especially the Grob. The only thing I agree with would be looking past move 1 for uncharted territory.

I don't know anything about this opening but I would guess that white's three thematic replies are 2 c4, 2 Nf3, 2,e4.Personally,I'd go with c4,expecting a transposition to Chigorin defense.
What pfren is talking about is a few abherrent players out of hundreds or thousands of players who often play those moves in:
1) Blitz.
2) In simul.
3) To avoid their opponents specifically preparing against their openings.
4) To increase their publicity. Every time the word "Short" is mentioned anywhere, that slightly increases Short's notoriety and value.
Short does not believe 1. Nc6 is actually "good", only that it's playable and not immediately losing.

I just checked it in fritz,it seems there are basically two thematic moves after ..2 e5, 3 d5.So,1 d4, Nc6 2 c4, e5, 3 d5, Nce7 4 Nc3.Or,1 d4, Nc6 2c4, e5 3 d5, Bb4+ 4 Nd2.

It's perfectly OK, Short has played it many times.
Shows how much pfren knows about Chess Players ? & Chess in General
Nigel Short is known as "The Biggest Spoilt Brat in Chess...Never to Become World Chess Champion"
https://chess24.com/en/read/news/sutovsky-calls-short-s-commentary-disgusting
You seem obsessed with commenting on every one of pfren's posts, like some kind of weird fangirl. Just pointing that out.

Back to chess,the way I see it is that Nc6 as a response to d4 is a chameleon opening,having both independent value of its own,as well as offering a wide range of transpositional possibilities.All in all,fully playable and rather better than it looks.Just my opinion..

hmm...I've played that same trap before in a similar position.I think it also arises from the Marshall Defense (1.d4 d5 2.c4 Nf6).Interesting.

How about 2 e4 guys?Well that would transpose to a Nimzovich defense,wouldn't it?
yup.The Nimzo defense is solid.
This defense is characterized by 1.d4 Nc6.In essence,it looks like d4's counterpart to Alekhine's defense.I've played this a few times,and the results were mixed.Is it sound?Any lines in this relatively uncharted territory that kill black instantly?