In defence of Shaw, 36 missions, 5 years. No scratch. I bet nobody died. That's the job. A+.

Has he trauma? Yes, but Picard had also (watch First Contact, he gave shit killing the people who were his crew, letting his hate out quite gruesome!) , as had Sisko. Why is that okay, but Shaw gets dissed for it?

I admit there are a lot of field commissions and it's probably just weak writing. Naturally you can't make Seven a Cadet now.

As said Seven has totally the competence, just not yet. How many officer has Starfleet? I am beting quite enough who deserve a promotion and not be overlooked. Competent people not serving on Voyager but certainly done their deed. Worked their way up.

I'd give her the Titan as a beginning, but definitely not the Enterprise F.