Sins of the Syndicate

If you are doing this quest and no mobs seem to be available, it is probably because they are in "permanently stealthed" mode. Today is the first time I saw this, I am guessing it will either be something that is always the case with these mobs (makes sense for what they are) OR is seems to be one of the random buffs the zone gives to mobs whilst questing (such as the exploding upon death or such).

Best way to find these guys is walk through an area they are supposed to be on your mount to pick up a few attacking you, then AOE the area to see where exactly they are. They do not come out of stealth, as the buff states they are permanently stealthed, but you can very faintly see them when they are attacking you and in the vicinity.

Yes, the mobs here DO give Ravenholdt rep(and tank your Syndicate rep).. if anyone's still grinding that, although I'm not sure at what level that stops.

You can still do these quests even after your factions "turn" is over and the portal has disappeared. You just have to fly to Arathi Highlands in the Eastern Kingdoms. The fastest way I've found to get there is the take the portal in the Great Seal to Orgrimmar, then in Org take the Twilight Highlands portal and just fly to Hammerfall, it's right above Twilight Highlands. Once you're there be careful as it's the other factions "turn" so you may want to turn war mode off.

Once you've completed the quests you may think it's impossible to turn them in as the turn in area is destroyed and the npcs are gone. But they are actually back on the Port of Zuldazar and will accept the turn in there.