As a new 3DS owner (from New Zealand) I hate to break it to you, but the new 'nub' would be utterly unusable as a 2nd stick.
It has almost zero tactile feedback, its just a hard piece of rubber, the only way you know it's even working is the fact that when you push it, something happens on the screen, like a smash attack.
I believe that apart from a few rare cases like Smash, you will find it PRIMARILY used for camera control only.
As for Amiibo discussion, rumor is that once stock is gone, they will make "card" versions of the characters. This gives me hope that we will indeed see Marth being used in a future Fire Emblem game etc, and that the Marth "chip" is pretty easily available. However, the Amiibo itself will not be. I assume they will look like a credit card with a pretty picture. Also, if the card rumor is true, expect to see Amiibo supported well into the next cycle of Nintendo consoles. Amiibo is here to stay.