Note 2. When I hit my Bluetooth earpiece button it activates Samsung S Voice, which is terrible. While I'm not in love with google voice, I'd rather use that than S voice. Is there any setting or hack which I can use to have my Bluetooth earpiece activate google now?
Root your phone. Download titanium backup from the play store and delete all that useless Samsung bloat ware like media hub, Samsung music hub. Samsung push notifications. S Voice. And so on. Keep S Note though. You don't need any of the Samsung garbage and it sits in the background using RAM for no reason.
Or download a ROM that is pure vanilla android. You will be happier.
And I don't know about a BT earpiece, but in my car all BT commands work as they should, but I am rooted and romed and my car has A2DP Bluetooth syncing. Should work the same with your earpiece, but I can't say for certain, cause I don't use them. Hopefully, someone else can chime in here on that aspect.
Or head over to the XDA forums. Here is the link to the AT&T portion of the Note 2 side of the forum:
http://forum.xda-developers.com/forumdisplay.php?f=1870
If you are on another carrier, just use that "Find my device" bar at the top of the page. By the way, Telus, Bell, Rogers and AT&T fall under the same ROMs (as well as T-Mobile I believe).