A quick bevy of Tomb Chest related questions!Yes. You can stockpile as many chests as you want. Any DS inside is ignored for effects that look for it. You're allowed to use DS inside of chests to power DS-driven abilities, as long as you meet the requirements for the ability (i.e. you can't do something that is "Once per Turn" while in Town, as there are no Turns there).
Is there anything (other than anvil carry capacity) stopping you from stockpiling multiple tomb chests to store more than 8 hidden dark stone at a time?
For any abilities that consume dark stone for activation, are there any complications for using dark stone currently being stored in tomb chests or is that simply another perk of having them hidden away?
Presumably so, but you can saddle a tomb chest onto an ally pack mule without any issues, right?
You may NOT reactively take DS out of your chest to avoid having your Items stolen, once you're involved in that kind of an effect. For instance, if you roll a 3 on the Camp Site Hazard chart you might lose D6 Dark Stone to robbers. If you don't have enough shards on you (because say, they're all hidden in your Tombchest), the robbers will take your Dark Stone Items instead - at a one per shard rate. Once that chart result has been rolled, you must resolve it BEFORE you're able to to move your DS shards around*. So keep a few in easy-to-find places so you can protect your awesome Items.
Tangential dark stone question:Anytime, other than between when a Mission is considered "complete" (which in and of itself is a nebulous term) and rolling for corruption.
Can you discard dark stone at any time (such as when a mission concludes, if you're concerned about too many corruption hits?)
*because they're being imminently threatened. You can't mess with Items that are currently at-risk by some mechanic until that mechanic is resolved.