#1
so i am in the process of learning John Butler's The Ocean and i suddnely realize that i really am not hitting the octave notes on my 12 string when i play the single notes. i tried using metal fingerpicks, they havent worked out for me so good. i know butler uses his fingernails but that really isnt an option....i had the idea of restringing my guitar so that the high octave strings are instead *below* the regular ones.

has this been done before?

and

will it make the sound too bright, in your opinion?
#2
I'd keep it the same. You'll have to file a new nut and it's not going to be worth it. Keep working on the song. You should able to hit both strings with you fingers or picks. I play it with a thumb pick and fingers and you cant really hear the difference.