Late to respond, but:
My experience with Fearsome Stare has been with the Defender version, but even there, without the crit chance, the Presence pool was not remotely worthwhile. A reasonably slotted Fearsome Stare can keep the rabble mostly neutralized on its own, so you'd be spending at least two power picks and a pool choice to stack a soft control on bosses. Remember that Terrorized mobs can and will attack when they take damage, so fear powers are most effective as a divide-and-conquer tactic--you can use them to shut down a crowd of minions and lieutenants, then deal with the boss using your hard controls.
GuiltTrip makes a good point about Super Speed; combined with Shadow Fall, it lets you run around maps with near-impunity (though watch out for snipers--they can see through double stealth). Since Hasten is another very good pick, you'll probably already be taking the pool. If you prefer a different travel power, you could look for a stealth IO to slot in Sprint to get the same effect (or you could take Super Speed and respec out of it later, when you do get the stealth IO). Recall Friend is also a solid choice if you play sneaky, as well as for general team utility.
