hopefulacademyapplicant,
Congratulations! Welcome to the USMMA "family" and good luck in the journey you will embark upon starting in July. Also wow from your questions you are indeed excited and have a lot of them - totally understandable. Here's my thoughts and answers:
1) The academics can indeed be challenging, especially if you have a few "holes" in either your high school math/science preparation or have no real study habits and finding yourself needing to develop them for the first time. You've probably read this here elsewhere but basically a trimester is little other than a 16 week semester crammed into 13 1/2 weeks. As noted above - don't be afraid to either offer or ask for help. Find study partners in your academic section who you don't mind working with (and vice versa) and who you don't mind being around - then as the saying used to go when I was there "cooperate & graduate." Bottom line re: time management at KP, 95% of the time, rule # 2 for PCs (Plebe Candidates) is:
if you manage your time so you take care of your academics first and foremost then everything else works out and falls in line. It's easy to be confused about this as you exit Indoctrination and the Academic year starts since during Indoc, Plebe Candidates have nothing other than "The Regiment" to worry about and during the first week or two of a trimester things can and often do start out slowly, especially first trimester - that said loose sight of the above as rule number 2 for Plebe Cadidates and it will likely be at your own peril.
Rule number 1 is basically as others indicate:
While a Plebe Candidate, to the extent practicable - fly below the radar. You can't nor should you totally bury your own personality, and most midshipmen have strong personalities, but the truth is, there will be plenty of opportunities and time during your four years at USMMA to display your gifts and personality in spades - Plebe year prior to recognition, is really "not that time."
2) Not sure which of the many YouTube videos on sea year you're specifically referring to, but Sea Year is indeed for most KP graduates, the highlight of their experience at KP. It's a "work hard/play hard time"; and you get a great chance to see a lot of the world and to do it not as a tourist but as someone who is actually a working part of the countries you are visiting economic "engine." As such you'll gain a perspective, that, IMO is far more valuable then say going abroad for a semester as a "normal college student." Of course there are some negatives to the "work hard" part too - as in occasionally that might constrict your ability to sight see, etc - for example if you are on a container ship in China, in many ports your time actually alongside the dock might be barely 8-10 hours before the ship departs for the next port, etc. That said, I believe if you are "a good cadet" who works hard when you are needed, most Captains, Chief Engineers and crews, try to repay you by enabling you to enjoy and take maximum advantage of the experience; as long as when there is work to be done and you are needed "you deliver the goods." I know this is generic but the specific answers to your specific questions varies from ship to ship and crew to crew - also never forget to make some time to actually work on your "dreaded sea project" - failing to do so has tripped up more than one otherwise stellar midshipmen - there are just some things you can't complete in your sea project in that last week before you have to report back to USMMA for your next trimester.
3) In reply I'll ask - what kind of shape are you currently in? If you are a varsity athlete and basically stay in shape, while there may be one or two particular things that are hard for you initially, you'll likely do just fin both through Indoctrination and Plebe year. If you're not an athlete and/or are a smoker then i'd recommend you work on getting in better shape and running more before indoctrination starts. Summers on Long Island can be hot and "muggy" and the Indoc regimen has a fair amount of running, etc. Also it's always a good idea to try and stay in shape during your Sea Year - there are PRT's you need to pass upon your return to campus and the remedial classes, while not ridiculous do usually require you to participate in morning workouts before breakfast and given that the ability to sleep until normal reveille is a cherished "class rate" nobody likes to basically loose that privilege so they can do extra PT. Marine Ops is available and there may be some sort of Navy Seal prep courses, there's also other options, etc available and all that is best explained by current midshipmen (both those that participate in those options and those that do not) - additionally during you Plebe Year these things are all presented and made available to you as applicable. As far as your specific question relative to comparisons with what's available and offered at either USMA or USNA - my view is for those items that are useful, USMMA has all that stuff, only lots, way betterer - but hey that's just one old graduate's view
Best of luck!
Although their 'stick ships' being bought by U.S. Lines was some consolation.