If I give a potion to an unconscious PC, which character's RP is used? Or is it a choice? I imagine this would be tied to the narrative justification for what resonance actually is and how it's used.
I can support the design goals of adding RP, but personally I feel potions should be an exception. Since they're literally ingested and metabolized, they should always work. (Bulk helps eliminate the spamming issue vs a wand.) This would also allow them to consistently work on 0-level NPCs. Players could deliver potions of cure disease to a plague-stricken town (or whatever) and actually feel like they accomplished something rather than have half of them fail to function.
On a related note, can I loan my cloak of elvenkind to a 0-level NPC we're escorting through dangerous territory? Or would it not work? What if they had low charisma?
I feel like NPCs are now either operating under significantly different rules than PCs, or there are a now a whole heap of people who literally can't use magic items or potions due to having no level and low to average charisma. Or have I missed something?