1 charm = same
2 charms = trade
3 charms = random item
As to that question, I believe he was talking about having the option to use more than one charm on a single roll. So if you use one, it works the same as now. If you elect to use 2 charms, then you can trade a drop you have for a different one on that loot table. Like if you have the helm and you just got another helm, you could choose to use 2 charms and trade that for the sha-touched weapon. And finally for using all 3 charms on one roll, you are guaranteed a drop but it's random from the loot table.
Crazy thought on the subject of thunderforged gear vs valor upgrades. You've mentioned the idea of changing the valor upgrading system to a 3/6 ilevel boost instead of 4/8 boost so that a fully boosted item is equal to a thunderforged item (and the assumption that thunderforged items can't be upgraded). But what if they just left valor upgrades at 4/8 ilevel boosts and thunderforged gear at 6 (and non-upgradable). Then thunderforged gear wouldn't be quite as good as fully upgraded items but noticeably cheaper since you don't have to spend the 1500 valor points on them.
For example (if I'm remembering the numbers you gave in another video) if a heroic item is 435, the thunderforged version is 441, or you could take the non-thunderforged one and upgrade it to 443. Thunderforged items would still be valuable since they would be items that you wouldn't need to spend valor points on for a long time, but valor upgraded items would still be the best. I don't know, maybe I'm just crazy, but I sort of like the idea of "best item with an added cost, or slightly worse item with much lower drop-rate", it just seems like a decent tradeoff. And I think thunderforged items having a higher drop chance in 25s would still be a good incentive to keep people in 25s since they would essentially represent a chunk of valor you don't need to spend (since getting a fully upgraded BiS set would take a very long time, or simply not happen, so having a few of the non-upgraded slots be filled with thunderforged items only 2 ilevels lower would still be very attractive).
Again, I'm probably just being crazy and it would probably be just the same as if thunderforged and upgraded items were the same.
Sifu's probably right. Not sure I like that idea, though.
But yeah, if you loot an item you already have, having a "reroll" option that basically rolls again for you (so giving you a chance to end up with a bag of gold instead), would be nice.
Pancake: That would make Thunderforged look less attractive than more attractive. Even if you are unable to upgrade every single piece to 2/2, people will still look at a piece of Thunderforged and think: "Nah, that has less potential than this regular piece, so I'll just pass on it."