Came up in my first Carrock game (pack arrived today woot woot):

Can I use Strider's Path on a location just revealed from the encounter deck while The Carrock is the active location? Strider's Path doesn't target the Carrock directly, but its effect does affect the Carrock. So does this fall foul of the "immune to player card effects" text on the Carrock or is this a perfectly valid way of making sure the Carrock will remain in the SA for the rest of the game?

I would say that you cannot do that. It says "Immune to player card effects" and not "Cannot be the target of player cards". You aren't directly targeting it, but it is an effect from a player card.