Pretty simple, this idea.
Some missions should have a time limit. If you don't achieve the objective, you get blown up or overwhelmed by an unbeatable number of soldiers. Or a plot-critical character is executed before you can save them, or escapes from execution at your hand.
I didn't like it in KOTOR how you could leisurely scavenge your way through enemy corpses and storage bins, even in critical situations, like on the Leviathan.
Timed missions would add real tension and drama to the game. Excessive scavenging would be a risky proposition when there's a timer ticking down, and if there was some sort of reward for an exceptionally quick time, it would create a further dilemma. The plot could take different turns, depending on your speed.
And it's like the films.
Possible problems:
Just maxing out force speed and running through the mission, ignoring the enemies. Some sort of game mechanic would need to be worked out to make this an unwise course of action; enemies blocking the corridor, for example, or having to deactivate a shielded area.
It's not very 'RPG-like'. I don't care much for the conventions of the RPG genre, but some might object to what could be called 'twitch' gameplay.