The cunning sneak feature allows a creature to make a hidden check if they have any concealment or any cover. The wilderness skirmisher feat enables them to gain partial cover against ranged attacks when in a square of difficult terrain.
It seems that this should allow them to find quicksand, shallow bogs, and rubble and roll to go hidden. Does partial cover to ranged attacks provide the cover required for cunning sneak in order to roll hidden (and imo become incredibly op).
One counter I thought to this is a creature having reach. There would be no partial cover to this creatures melee attack, and so the rogue would not be able to become hidden to it.
EDIT: Will a person with Crossbow expertise, which lets them ignore the partial cover when attacking with a crossbow, be unable to be hidden from by the rogue due to wilderness skirmisher?
Cunning Sneak You don’t take a penalty to Stealth checks for moving more than 2 squares, and you take a –5 penalty instead of a -10 penalty to Stealth checks for running.
If you end your movement at least 3 squares away from your starting position, you can make a Stealth check to become hidden if you have any concealment or any cover, except for cover provided by intervening allies.
Wilderness Skirmisher Benefit: When in a square of difficult terrain, you gain partial cover against ranged attacks. Also, you gain a +2 feat bonus to Acrobatics and Athletics checks.
Crossbow Expertise Benefit: You gain a +1 feat bonus to weapon attack rolls that you make with a crossbow. This bonus increases to +2 at 11th level and +3 at 21st level. Also, you ignore partial cover and superior cover with weapon attacks you make with a crossbow