A real simple way to make intimidate a good skill would be to make ALL applications of it into a standard action. Then it could be used to stop a fight.
After that, you could make use of some rules I made up for it which are based on the degree of success.
You may intimidate once per round. You may intimidate an opponent that you have an unimpeded line of sight to(ie - that would gain no cover against you), and that can see you as a standard action.
You may take a -5 on the check to intimidate as a move action
You may take a -10 on the check to intimidate as a free action
You may take a -5 on the check to intimidate all opponents that you threaten
The DC is 10 + opponents hit dice + opponents will save bonuses + any bonuses vs fear
If you beat your opponent, he is shaken for 1 round plus one round for every point by which you beat his roll.
If you beat him by more than 10, he is frightened for 1 round, plus 1 round for every point that you beat him by more than 10. After that, he's shaken for 10 rounds.
If you beat him by more than 20, he is panicked for 1 round, plus 1 round for every point that you beat him by more than 20 after that he is frightened for 10 rounds and after that he is shaken for 10 rounds.
If you fail your intimidate roll by 5 points or more, you cannot intimidate that foe again until you gain a rank in intimidate.
This does mean that intimidate becomes quite powerful. Enemies will flee quite often against an intimidator.
Mind you, this is nothing compared with say turn undead.