I'm interested. But lazy, like a lot of people who previously posted. I'll beta test, and help with the story.
I also have a suggestion for the multiple Link's issue, unless you already solved that yourself.
How about if the online game had 4 people from around the world, (the selection is random, unless you request to play with friends from a friends list or something), in the style of Four Swords? Instead of one world where 50,000+ Link's run around, each "group" of four people get there own "world", or a private level of their own, to complete. Obviously, this would mean it isn't an exploring overworld, but like something similar to
FSA's level system.
EDIT: Or to save space or increase online play, you can change the number of Links per group. Maybe 6-8 Links instead of 4?