Your ECs are NOT lacking - they’re pretty good. In fact, congratulations on your many accomplishments.
Now regarding your questions:
There are also no “lower” Ivies. There are the ones with higher or lower acceptance rates and ones with more or less name recognition.
While you will be competitive for all of the colleges on your list, they are all reaches for anybody. Moreover, there are many highly qualified applicants from your country, and you will be evaluated against them, not against the bulk of applicants who are from the USA. Of your list, only Amherst is need blind for international students, meaning that the rest will consider your ability to pay tuition before they decode whether to accept you, and they will prefer to accept international students who can pay full tuition.
What are you looking for in a college? It is difficult to provide you with advice, based on the list you have, since they are all very different colleges, so it is difficult to figure out why you like these colleges, except for their low acceptance rate and high USNews rankings…
While all of these are excellent schools, and if you were an American student, I would recommend them very highly, the financial aid that they have for international applicants, and not being need blind in admissions may hurt your chances, or, if you are accepted, they may offer enough aid for you. So check them out, but also check what financial aid the provide for international students.
If you will be serving in the military when you return after your degree, there is no reason to mention it. If you will be serving between now and when you apply, it is difficult to say exactly what the situation will be in another two or three years.