As it stands, locked containers such as crates, lockers, lock-boxes, and safes present a nearly insurmountable barrier. With the exception of shooting locked crates open, there is no method known to me of unlocking these containers other than with the appropriate ID access.
My concern for this difficulty is less of a balancing one, and more of a realism/RP one. A metal locker, in real life, would fail against the persistent swinging of a fire-axe, for instance.
My suggestions:
1) Brute force
Attacking locked containers with weapons such as fire axes, energy swords, etc. should open them. The "health" values of the containers could be adjusted to balance this. Additionally, the process should be quite noisy (e.g. as loud as attacking a grille).
2) Pry/Cut
Tools such as crowbars and mining drills should be able to pry or cut open locked containers. The time required to pry/cut the container open could be adjusted to balance this. Some containers may be too strong to pry open, such as metal cargo crates. As I imagine it, prying/cutting would be a quieter method than brute force, but it would take longer.