My mind is too undecided to just choose 'yes' or 'no'. So I hope it's alright that I write my thoughts down. If it isn't alright... well, then there isn't really much to do. Because by the time you read this, I will already have written it.
I think that if there is unactive people, they should be killed first. I think it would be unfair if someone active was killed, when another player hasn't been active for months.
I agree that it would be somewhat more interesting if we can't be certain to survive.
But I know that I would be really sad if I suddenly wasn't a part of 10 Doors because of bad luck. I don't know if other people feel the same way.
But maybe that person could be offered a new character right away. So it's only the character that is dead, but the player is still a part of 10 Doors.
Though if that were to happen, I hope you won't kill of people all the time. I think it would be too confusing, if too many people died all the time. It is limited how many characters you can really connect with. Especially if they aren't even the the RP for that long.
When the Villain makes new games, the one who loses might not have to die all the time. Sometimes that person could just be tortured. Though you don't have to tell us whether the person who loses will die or 'just' be tortured. That way it could still be interesting, in my opinion at least.
To sum it up, I don't think it would be unfair, if:
There isn't any unactive players who could die first
If it doesn't get too much with too much killing and too many new characters all the time
If the active player can get a new character right away
Sorry it got a bit long ^^"