USNA Chinese Major
Hi elds, great to hear you're thinking about a service academy.
I'd like to tell you first hand since I'm currently pursuing a IR/Econ/Chinese triple major.
I have no prior experience with Chinese. However, I was selected for the semester abroad as a sophomore simply because of the effort/aptitude I have for the language. This is tangential to the fact that although having prior experience with the language is definitely not a bad thing, it can in fact hurt you. My competitors involved people that had HS/foreign living experience with Chinese, but the teachers constantly rag on them for their bad habits and inaccuracies. I have surpassed many of them in my endeavors, as well as juniors and seniors above me, and it sounds like you have a good talent for languages, too. My position is, as long as you work hard, you'll be fluent before you leave anyway, so the starting point is practically irrelevant. I plan to be spending a grand total of almost a year in China including my summer opportunities and semester abroad. USNA is very supportive of language learning.
That said, I would kill to be doing what you're doing right now. That's pretty amazing.
As far as the actual major, I'm kind of working my matrix to not take any specific classes around the major and still achieve the major (through overlaps in Econ/IR), but I would still highly recommend it. As far as the actual classes that I have experienced, the teachers are world class. You, especially, will have a great experience with it;the only bumpy part is the plebe teachers that aren't actually language teachers and aren't totally fluent in English yet.. haha.
Overall, there's a huge focus on speaking, and the teachers doing it have been at it for their entire career. We of course learn writing and reading is a duh but we usually give presentations to the class at least once a week, consisting of preplanned "speeches" for a minute in as fluent of chinese as possible. They make sure you learn CORRECT Chinese.
My one criticism: if you're serious about languages more than anything else, in retrospect I would personally think about West Point or Air Force. We get 3 hours of language classes a week, they get 5. It really is a huge difference. I hate to sell out my school, but yea. Good luck on what you decide!