They do stack. You can even stack BDS 2x if it’s from the same player(low level characters can reduce Cool down via tree root crystals), but apparently BDS via Pandemic + normal BDS doesn’t stack right now (at least from what I’ve seen in videos, I failed to extract my vaivora and my only PD is too low at level to equip the base weapon to test).
The only time when it didn’t stack but would overwrite each other were the times before Re:build if I remember correctly.
For the party buffs, they overwrite each other if it is the same one, so if a Priest with a bad SPR amount casts Aspersion after the Priest with the good SPR cast his one, you will have the Aspersion from the bad SPR priest since he was the last to use his skill.
There are exceptions to the rule, though, for example Paladins Resist Elements, which cannot be overwritten if it is the exact same buff (both having the basic effect or the attribute effect), so if the other Paladin cast his Resist Elements, even if there is only 5 seconds buff duration of the first Resist Elements remaining, the second Resist Elements will not be applied and the skill will go into Cool down without having any effect.
In general there is a lot of trial and error when it comes to buffs and their effects, the game doesn’t really explain how they work, which stack/can be replaced and which do not.
No idea about the Revive & Reincarnate thingy (there is also Revenged Sevenfold with arts to add to the mix), but if Reincarnate doesn’t trigger first, I guess the skill will go to waste because the buff duration is so short (same with Revenged Sevenfold).
Could be that just the order the buffs are applied in that matters, but certainly would be interesting to know, maybe someone else can answer this.