Nit: it's not pawnch-kee if you're speaking American English, it's more like pown-chkee. But still not quite.
* There is no individually-pronounced "n" sound; it is built entirely into the nasalized vowel.
* The /ʂ/ sound is actually a laminal retroflex. This is best described as making a "sh" sound, but with the blade of the tongue.
People form other countries just can't get it right :)