Hi all. I thoroughly enjoyed HoA - and the whole series. Being a new poster here, I can't prove to you what I predicted and what I failed to predict, so the strutting and blushing will just have to happen in the privacy of my own head. Anyway, here are some particular comments/questions/strawmen.
1. Anomaly among the temporal metals. OK, I've seen the comment that two metals are diagonally opposite when they ought to have been adjacent, but I also find it odd that gold is described as letting you see into your own past. When Vin burned it in FE, she saw alternative versions of what she might be now or in the future. If that's looking into the past (like seeing one image of the Lord Ruler in his packman days), then it's somehow done a U-turn and worked its way forward in time again.
2. Useless silver. Did we ever hear of someone trying to burn silver? Did it cause a 'bad metal headache'? If not, perhaps it simply lets you see your own past, which you don't notice because you remember it anyway.
3. Aluminium mistings. Yes, that would be almost pointless. But if the link between ingested aluminium and Alzheimer's disease holds, at least you could protect yourself by burning it away as it arrives in trace quantities in your food.
4. Chromium mistings. What would they be called (as in Lurcher, Rioter, etc)? I'm guessing it'd be unprintable. "Heeey, some [unprintable] just depleted my metals!"
5. Voices in heads. Since POV characters think to themselves in italics already, I assumed that that was what Spook was doing at the times when Kelsier spoke to him, and that the one about sharing the possibly-vital unique piece of the puzzle was an extraordinary burst of intuition. Good smokescreen, and/or silly me. ;-)
6. Zane's creepy fetish. I hope this is OK to mention here, since it is in WoA. Now that we know more about spiking, it seems like he wanted Ruin somehow to 'participate' with the herbalist (whose name I forget) and with Vin. Eww.
7. Movie/TV adaptation. I kept pausing while reading, to wonder about that too. It'd probably feel grimmer, because the red sun and bedraggled plants and ash would be in our faces a lot of the time. No relieving spells of getting distracted by the dialogue and plot. The ending could be a bit reminiscent of the original release of Blade Runner, what with its sudden wholesome and happy appearance. I can certainly imagine the promotional posters... A scarred forearm and hand, perhaps holding a coin, with the caption "I am hope"... that sort of thing.
8. Mormonism. I probably wouldn't recognise a distinctive LDS doctrine if it bit me, but it was interesting that the ending had such a strong "The meek shall inherit the earth" theme - a generic Christian thing. See who's left. Spook minus his spike, Beldre, Breeze, Allrianne, and Ham who recently came out with a rare piece of unequivocal advice against storming Fadrex City. All watched over by Sazed. OK, Marsh is more arguable, but his POV chapters do have a bit of a running-away-from-things theme.
9. Who wrote the epigraphs. Once it turned out to be from the current era, I also thought of the scholarly characters: Sazed, or Elend reverting to his pre-Tindwyl ways. The "I am, unfortunately, ..." wording in a Sazed POV chapter made him seem too obvious, so I started casting around for another twist, and ended up thinking it was Sazed as a ghost-writer for Vin (who doesn't much like reading and writing). Whoops. Overreached on that one.
10. Symmetry. Since there's so much overt symmetry, I went looking for more. Consider a love triangle, where the happy couple both die as self-sacrificing martrys, and the third wheel ends up still alive and very powerful. That could describe Elend-Vin-Spook, or Kelsier-Mare-Marsh. Or I could be overreaching again.
11. Trust. Great choice of title for the final part! One of my favourite things from FE and WoA was how Vin gradually overcame her abandonment issues. For instance, I was going "YES!" on the inside when she chose to turn to Elend first after her fight with Zane -- throwing aside the I-can't-let-him-see-me-like-this anxiety. And then, in HoA, the abandonment issues turn out to be part of the plot, not 'just' free-standing character development. Again, "YES!" And so much of the final denial of Ruin depended on people doing what they could and trusting that it would make a difference.
12. Martyrdom of Vin and Elend. I have no problem with it. They'd been prepared on previous occasions to lay down their own lives (and each other's!), but happened to get away with it. A story would be too bright and cheesy if everyone who took heroic risks always survived. And in this case, they were already both thoroughly on board with the whole trust thing.