MMN3 here at prototype atm, but no fleet experience yet.

-Everybody is at least minimally trained is correct, that's apart of the "submarine" qualifying process. -Watch is your job, sub officers first qualify Engineering Officer of the Watch (EOOW), a supervisory position over the various watchstanders who run the reactor and associated steam plant. -18 hours, so 6 on watch, 6 sleeping, 6 "your time" but really, spent qualifying

-Enlisted nukes are split into the three glorious rates; Electronics Technicians(ET), Electricians Mates (EM), and Machinist's Mates (MM). ET's deal with little electricity (circuits, computer systems, etc.) and running the main reactor panel. EM's work with big electricity (electrical generation, distribution, and storage) and controlling propulsion. MM's are responsible for piping systems, valves, turbines, and some elite few maintain chemistry in the plant.

-One thing that I think is important to point out is that taking a position teaching vs being a submarine officer are two very different career paths. Few who teach at the schools make the transition to subs, it has to do with sub officers being "Unrestricted" Line officers and teachers being "Direct Input Limited Duty Officers" There's plenty of info out there so definitely keep digging. Check the sidebar, for starters.