Hey, I looked over your letter, and you have some really good information down. I edited a little, and will detail the direction I think you should go.
Note: these are just my suggestions, dont feel obligated in any way to change something you feel is stronger in your opinion.... just want to help, like many on here have helped me.
Paragraph 1:
-opening line, " I have received the prestigious honor" or "I have been accepted in the BDCP(spell it out like you did)
-second phrase, ditch "prestigious" in front of supply corps.
-ditch "in any way" both times in the last sentence.
-ditch, "that has been given", you can change that to "bestowed upon"
- so your last phrase can read " I am not unhappy or disappoined with being selected for the Supply Corps, nor am I unappreciative of the amazing privilege bestowed upon me in the form of the BDCP."
Paragraph 2:
-rather than "I am able to learn well" think of something like "I am motivated to learn, and I am able....." that flows better
-put a comma after "interviews" and after "campaign" that seems like a good break point
-ditch "all" in that sentence: "....mission that were crucial to the...."
-rephrase the beginning of the next sentence " I did not have experience in the assignments I was given, but learned....."
-ditch "resoucefully" after the comma. The actions you list show that you were being resourceful.
Paragraph 3:
-Ditch "Personally, I believe": be confident. tell them. "I will be a Naval Officer first, and my specific job will..... "
-ditch "thus" : so it will read "Regardless of my designator, I have.... "
-ditch "a" and "that is" in the rest of that sentence. "being professional, hard-working, intelligent, and effective" you could even drop intelligent and it would continue to convey a strong positive message.
-the rest of the paragraph flows well, and i think is very good
Paragraph 4:
- ditch the "and" in the second sentence. It runs two thoughts together. Take the second half "love to read and learn", put it together with the 3rd sentence. would go something like this " My love of reading and learning enables me to continue researching a topic until I have found the answers to my questions. I will exhaust every resource availible to me during my studies as well."
- you dont need the Europe/Somalia examples
- ditch "both" at the beginning of the next sentence. "As a student of Economics and as a person, I naturally...."
- rephrase "I do not do...." later in the paragraph: something like " My research is not only for personal enjoyment, but for informing my collegues of current events, etc."
- Last sentence of the paragraph is good. rephrase slightly "whether it is a squadron.... he is briefing" to "whether its is briefing a squadron or the Commanding Officer of a ship."
Paragraph 5:
- 3rd sentence can drop "that this" and drop "any"... I dont know if there is a way to clear up or reword "strategic level brief is critical" if it doesnt need anything leave it alone. This is the only thing that threw me for a second.
- last sentence put a comma between squadron and ship. ".....best benefit the squadron, ship or unit I am responsible for briefing." you can drop "that" in the sentence as well
Paragraph 6:
-change "any" in the first sentence to "the": "......to complete the task at hand."
- last sentence is good. spice it up with some strong words. "I strongly believe that my skills and qualifications can best serve the mission of the Navy as an Intelligence Officer. Thank you for your time and consideration."
All in all this has a lot of very good information, just some fine tuning and it should be good to go. As noted above, these are only my suggestions, use what you want, discard what you want. Good luck to you, and PM if anything isnt clear, and I will do my best to explain.