Dumas, for your latest suggestions, I really like the effort you put in to give some bits of Ravenloft lore in their backgrounds, but I'm unconvinced they'd be good additions as they are now. Bear in mind though that this is only my personal opinion, not necessarily that of the staff. But my main concern when desiging a good Ravenloftian item, is that it must have both bonuses and penalties applicable at the moment you use the item.
For instance, your "Cameo of Glamour" is obviously an item that would only ever be used in roleplay situations. Giving it penalties applicable only in battles renders those penalties moot. I'd give it a penalty on some other skills instead, I'm thinking both appraise and spot, as the glamour's magic tends to hide the true nature of things, so would the wearer abilities to perceive the true nature of things be affected in some ways too. I also see no need for an item that casts "Charm Person" to have influence bonuses. You want the amulet's special properties to be used after all. But the glamour could help for performances and such. Note too that were not too keen on "uses by day" items, it tends to make those items immensely powerful compared to others. You'll have better chances of seeing items added in with "charges per use". Not that a "use by day" item can't be added, but be sure to have a severe drawback to bite back the user. This is Ravenloft, nothing of power should be without consequences.
So for your Cameo of Glamour, I,d see more something along the lines of : Charm Person (10) [5 charge per use, 50 charges], +2 perform, -2 appraise, -2 spot. That seems more balanced to me.
Similarly your Lightless halberd is a formidable weapon without formidable defensive hindrances. The kind that would make it the only halberd, halberd users would want to use. That's not what we aim for. I would have it with heavy penalties to at least 2 of the following: Discipline, Parry, Tumble or AC.
And your "Dementlieuse Boarding Axe" has 4 perks, for a single +10 pound weight. Granted its not a powerful weapon per say, so it's not a big deal, but I'd add some penalties to Discipline, Parry, Tumble or AC as well to counterbalance.
About the ring of oath, both clerics and paladins already have items granting bonus spells slots. I doubt we need more of those. But let say we do add them, what offsetting penalties do you propose?
I like the idea of your Vos Boyarsky Boar Spear, (we need more vorostokov stuff), but weapons should not grant AC bonuses. I'd say we drop the AC bonuses and Parry penalties, and reduce the tumble penalty to -3. That would be fair enough I think.
As for your ring of agony, it is really just way too powerful I think. Combine 2 of those with an Heart of Ice amulet and you get +14 to your will saves. For penalties that rarely ever affects the wearer, except sometimes for the fortitude penalty which should technically be higher than the Will bonuses in this case (Always following the logic that in Ravenloft uber items have even bigger penalties).
For the Waraji of the Lost Hero, we already have some boots granting reflex bonuses, and freedom of movement is easy enough to get through other items. I just don't see the purpose of adding them.