That is a pretty intense theory. I never thought of that. . . but then why the metal spikes?
Honestly, I was just throwing something out there to match some of the other speculation. I am still trying to form my theory about Hemalurgists. Perhaps when a Mistborn burns metal or a Feruchemist taps a metalmind, they give off power which can be collected by the spikes of a Hemalurgist. This would explain why their rooms would be so close to the Lord Ruler's throne, because he is always burning age, which they could use to keep themselves alive longer. For Zane, it could be that his spike feeds off atium, so when he burns it, he only needs to burn it very slowly because he has it's effects doubled. Who knows. THere's still much to think about and discover.