I didn't see a question in there at all. What information are you hoping to gain by posting on this site? Are you trying to get opinions on your game plan?
To clarify: you're going to go tens of thousands into debt with school to become an RN and then work for 1-2 years making $50-60K per year. Then, you're going to then enlist as an E-4 in the Army making about half that. All the while, you'll have to obey orders from higher-ranking NCO medics and officer RNs who may know less than you? To me, that would be miserable.
If you want to be a medic, why are you doing nursing school
at all? EMT-Paramedic would be a lot more applicable and useful to you as a medic in my opinion. It would also be a lot quicker and cheaper.
If you want to do more of the combat medicine the enlisted medics do, then why not be a civilian nurse and enlist as a medic in the reserves? I'd highly recommend the Air National Guard as a para-rescueman (PJ). PJs are arguably the most respected, best-trained, and most decorated medical personnel in any branch.
Your average enlisted medic/corpsman in the Navy, AF, and Army can have widely differing experiences. Some are basically glorified CNAs working in stateside base hospital. Others get really good combat medical experience. There aren't really any guarantees. I'd caution you against thinking you're going to be able to re-enact the movie Hacksaw ridge by enlisting.
At a minimum, I'd ask you to please find some currently serving enlisted medics and ask them about their experiences. I work with them every day. Many of them don't feel that they are doing what they thought they signed-up for. Others like it. Just know what you're getting into before you sign-up.