Which killer do you think each survivor fears the most?

Lore wise? Who knows. Most of the Survivor's came packaged with another Killer, so perhaps that one. Nea would fear Nurse the most, Feng would fear Doc... There are a few chapters and paragraphs that don't follow this though, like Ghostface and Ash, but the Survivors that came packaged alone (Bill and Ash) are badasses, so maybe they wouldn't fear anything. The killers that came packaged alone... Idk, maybe they're an enigma to the survivors.

Game wise? Spirit or Nurse.

mostly from jump scares. Also, the idea of walking into trap is a good constant fear in the match.

Lore wise taking cutscenes and trailers into account.

Definite fear

All of these have the common connection of establishment it seems they have been around for long enough to know what these Killers can do or at least have been in a similar situation to know that they should be afraid.

Claudette, Dwight and Jake - Are all afraid of the Trapper as seen in the opening cutscene.

Min - She is afraid of the Doctor during the Sparks of Madness trailer she immediately starts hiding upon hearing his breathing and then the second he shows up behind her she immediately screams and runs away.

Cheryl - seems to be afraid of pyramid head you can tell this by looking at the reaction of her eye when she's peeking through the door during the Silent Hill trailer.

Èlodie - she is afraid of the Twins she immediately starts cowering in the corner not even trying to help David when's Victor and Charlotte show up.

Unknown.

Yui - while she does give Oni a bit of a stare down (or up in their case) this is the first time she's ever been dragged into the entity's realm so she probably has no idea how dangerous he is so we can't really use that as a determination of fear.

Especially when you consider all the examples in the definite fear category have dealt with these guys before. ( in Cheryl case she's probably dealt with enough Silent Hill nonsense to know she should be worried even if this is her first time encountering pyramid head)

Kate - we don't actually see any frightened reaction to clown directly she's pretty much of startled by the bottle shattering so we don't know her genuine reaction to Clown himself.

David - considering Frank was tricking him into thinking he was a survivor we don't know if David is genuinely afraid of any of the Legion members.

But considering that Frank's trickery was able to work out David probably hasn't had much interaction with the legion that probably being the first time he's gone up against them or at least the first time he's gone up against Frank.

However he's killed off before he can even fully realise Frank is a threat so can't determined fear on that.