Just for the sake of speculations had anyone thought this Trilogy to be a war between two titans, harmony and Marsh?
Since the earring was given to wax by a kandra (supposedly loyal to harmony) which enabled harmony to interact with wax (like ruin and Vin, a voice in the head). I say this because after reading some posts here I know how Brandon likes to live clues and his telling that a kandra gave the earring to wax after which he mentions how harmony interacted with wax seems like a clue enough.
Why I mentioned Marsh is simply because of his appearing at the end, since he is the only one who is both a allo and feru (which made TLR almost immortal) that also makes him possibly the most powerful thing alive. Appearance of Bloody tam is another reason to point out marsh's involvement because at this point in the story I beleive the only one who knows about hemulargy on scadrial so if bloody tam used hemulargy then he probably had someone who taught him. Since Marsh is powerful enough and with power comes desires. probably he is planning to overthrow the current government and establish himself as The Ruler of Empire. Now another question might arise that why he waited for 300 years, how about applying the Kelsier theory of Atium production starting again after 300 years, since the only one with the knowledge of Atium I believe this is the thing that will give Marsh an edge over others and is worth the wait.
I read someone mentioned that now Atium will not grow because harmony now carries the power of ruin but what harmony controls is what was remaining of ruin(-Atium) because ruin hadn't reclaimed atium it was burned away by elend and others so hopefully that power was spread around the universe and is now returning in the form of atium.
Since harmony now have no human form he needs a human to stand against Marsh, wax makes for an obvious choice as he is a allo and is from the bloodline of breeze, old friend of harmony.
I don't know from where it all came from, I guess too much of alcohol can do this to you.
The only thing which I am not able to figure out is the kidnapping of women but since they all are from the bloodline of spook I beleive that the reason behind kidnappings is connected to allo.