Hm, but aren't Semi Vanilla creatures the ones that have an effect but doesn't need to be triggered at all? I've always thought of it that way, so that's why Dune and Voodoo are on there. RoL is only there because I didn't want to put on Archangel for the only upgraded Light creature (although I suppose Pegasi could work considering it would have to be a trio).
No.
Vanilla means no abilities.
Semivanilla means no abilities that affect the balanced cost of the card. It was coined to describe cards that were balanced as if they did not have an ability but did have a flavorful ability (Burrow, Airborne, Undead, ...)
When it was coined some included effects that were one use that would leave a vanilla creature (Werewolf) to describe how the creature would become vanilla quickly.
Abilities that don't need to be triggered are called passives, and if they can be lobotomised, they are passive actives.
The card's a neat idea, but imo 'vanilla' is too arbitary with the cards we have currently in-game. I personally would make the beacon just produce weak (low atk) and/or small (low hp) creatures, but I dunno if that fits the thematic values you had in mind.
No. Passive abilities are the abilities that can't be lobotomized. Active abilities are the ones that are in the active ability slot (creatures can have as many passive abilities as they want but only 1 active ability like Vampire or Growth). The naming comes from the code, not from being "activated".
Darkness should not get Voodoo Doll(obviously not a semivanilla).
Voodoo's only ability is the Voodoo passive, it has no active ability. I'd say that it's even closer to vanilla than semivanilla.
Vanilla means no abilities.
Semivanilla means no abilities that affect the balanced cost of the card.
Voodoo Doll's entire point is its ability therefore it is neither Vanilla nor Semivanilla.