Loved this topic and theory.
Seems to fit nicely, but the problem is that we don't have enough info, it's like we're trying to conect 2 dots with a line, but we don't know if the line is straight, or if there are any points in between that curves the line...
A little off-topic now, does anyone knows why does the shardplates need to be fueled with gems, but the swords don't need it?
It almost seems like the plates could be linked to the person the same with the blades, and when they disapear, they go somewhere where they are recharged, but since people don't know/remmember how to bond with the plates, then they need the gems to fuel it, and maybe that's why the radiant's could summon their plates(the guy that summoned his helmet) as well as the blade.