Some questions for those with the MOS 5821.

Hello, Marines.

I'm halfway through college. I don't want to be here at all, but my parents want me to have a degree and I owe them everything.

Since my junior year of high school, I wanted to enlist and get experience in law enforcement from the Marines. Whether I stay in for life or use it as a jumping point to get a similar job in the civilian world, I'll decide when I get there, but I definitely want the structured and professional atmosphere of the Marine Corps to prepare me to be an investigator.

I've met lots of service members and learned a lot about how they work, but I've never met a law enforcer for the military.

Things I've found out through my research:
Carefully read enlistment contracts, preferably with a current service member you trust over your shoulder.
5821 is not an MOS you get straight out of training. You must be a Sergeant among other qualifications.
The daily life of an investigator is not at all like TV shows like CSI or NCIS.

Here are my questions for you:

What's your chain of command like? Who reports to who? Who does what?
How similar to civilian units are you? Is it like working in a local PD?
Would you say your work teaches you a lot? Are you prepared to work in a civilian unit if you had to leave the Marine Corps?
If you had the opportunity, would you have taken the officer route for the same area of work? Would you prefer the job of the officer above you?
Were you promised your MOS? Is it even possible to secure in writing you will get the MOS you want with a recruiter?
What's a good MOS to prepare for 5821? I would think a normal progression would be from 5800 to 5811 to 5821. Is 5800 an MOS you can receive right after recruit training?
For reservists, is your civilian job in law enforcement? Can you even be a reservist and have the MOS 5821? One thing I was considering doing was being a reservist with the MOS 5821 and also work to get into a federal law enforcement agency.

Thank you for entertaining this post,
Phillip.