Zyracksis

Do they mine gems? Or do they get them from animals, like they do with the larger gemhearts?

We have a recent WoB that Autonomy helped Odium splinter Dominion and Devotion. It seems natural that Odium would be paired against Devotion, and Autonomy would be paired against Dominion. So it's more likely that the svrakiss are related to Autonomy instead of Odium. This fits with Bleeder's actions which seem to fulfill the intent of Autonomy

The implication of Secret History is that what Vin noticed was Kelsier warning her not to. It seems likely she'd have been able to sense it somehow, given her bronze hemalurgic spike enhancing her ability to sense magic stuff.

Edit: post removed due to Secret History spoiler rules. Note that we can't talk about this or BoM even with spoiler tags, outside their own boards

The new Elantris Ars Arcanum mentions that the Elantrians channel the corpse of their God. This would mean that they are indeed drawing power from a shard, albeit a splintered one. Perhaps someone can get the exact quote, I can't access my copy right now.