Any chance these are in game and we're just missing them, or do they perhaps drop off raid mobs and/or heroic mobs and we've been just unlucky or are we suppose to unadorn them off of preadorned stuff? No idea.
No there is no merchant. You have to destroy items to get them... see my thread about why the new adornment system isn't good =/ http://forums.station.sony.com/eq2/index.php?threads/pre-adorned-items-and-why-its-a-bad-idea.697/
I didn't catch that, no. Meh, that's pretty lame. So literally, just right click and destroy and the adornment pops off into your inventory?
No, there is a tinkered adornment extractor you need to make/buy and it removes the adornments and destroys the item in the process.