Not to get too nitpicky or anything, but everything we've seen Starfleet do can be and has been done by most navies or other military branches today. The only notable difference is that Starfleet has a larger science division than navies/militaries of today. But this is a necessity of operating in space, not proof that they any less of a military.
The Green Mushroom wrote:
Junior Officers (including Worf, Wesley, LaForge, Chekov) are given command uniforms and then allowed to work in several departments until making a decision. They are not all that different from first and second year Coast Guardsmen working under a BM before choosing/being assigned a rate.
This example means nothing given that three of the junior officers you cited were helm/navigation, which is a command officer's post.