I write a site called "Approaching Aro" that may answer most questions. There's a "Controversy FAQ" there that might be particularly useful.
Here I'll answer some of the questions that arose in the closed thread, and pose a few new ones.
What does ngak'chang mean?
It means "master of mantra". It's a common Tibetan term, spelled sngags 'chang. You can find it in the Rangjung Yeshe Dictionary online, or probably any other Tibetan dictionary.
re: Aro in general: its fun to play dress-up!
Ordained Aro tantrikas wear traditional ngakpa robes. Those are not unique to Aro. They are an aspect of the non-monastic system called gos dkar lcang lo (pronounced gö-kar-chang-lo), which is most common in the Nyingma but actually found in all four Schools. You can find this in the Rangjung Yeshe online dictionary too. "Gos dkar" means "white robe" and "lcang lo" means "long hair".
Lots of non-Aro folks who dress that way, notably the ngakpa community in Repkong, Amdo. It was not well-known in the West until recently, but there are now many people, both Tibetans and white folks, teaching on it. One particular proponent is Dr Nida Chenagtsang (an ethnic Tibetan, from Repkong) of the Ngakmang Institute. You can see a picture on his page at:
http://shrifreedom.org/Tibetan%20Medici ... gtsang.htm
which shows a group of Tibetans in attire identical to that Aro wears.
Most Aro practitioners do not consider gos dkar lcang lo "fun". It's a pain in the posterior. It has an important religious function in non-monastic tantra lineages, however.
they dress up like that to do the exact opposite of what non-tantra lineages do.
This is pretty much correct...
Instead of dark robes they wear white which symbolizes death...
This is not correct. The white was originally natural, undyed cotton, which symbolizes the unaltered Natural State, i.e. Dzogchen. (Nothing to do with death! Usually white in Tantra symbolizes bodhicitta. Offhand, I can't recall its ever being symbolically associated with death, although obviously bones are white.) Nowadays the cotton is bleached, which makes hash of the symbolism but maybe looks nicer.
wear ridiculous hats, non-celibate, act vulgar... crazy wisdom type stuff
"Ridiculous" is a matter of perception, but I agree with you about that! However, the hats are again traditional within the Nyingma, and not specific to Aro (except in small details).
Like most ngakpas, most Aro practitioners are non-celibate. (Is there a problem with that?)
Vulgarity is strongly discouraged by the Aro Lamas. (We may fail to live up to that recommendation sometimes.)
None of us, including the Lamas, attempt "crazy wisdom". "Eccentric decency" is what we aspire to.
They're a bunch of fakes and this is widely known.
What does "fake" mean? There's a couple hundred of us, and we are real people. Fake what? In what way? How do you know?
And, who knows this? (As far as I can tell, this "knowledge" is confined to a handful of forum posters, formerly of e-Sangha, now here.)
Best wishes! I'm happy to answer any questions about Aro, as best I can.