I'm not much help in terms of recommending schooling but i would not be too concerned about sitting in front of the USCG for the exam. In fact, I was unaware of any school or organization that was authorized to administer the USCG exam. The maritime academies hold the exams on campus, but under USCG supervision. I've sat for four exams, plus renewals of my Master's license, and the proctors are generally USCG enlisted men with little or no knowledge of the exam. They do not even have the answers, let alone the knowledge to explain any confusing questions. They are merely proctors, charged with ensuring that you have not secreted the COLREGs away in your shirt. The exams are actually administered out of Oklahoma City, Oklahoma-a noted deep water port.(G) That being said, I've found the CG in Baltimore to be rather amiable by comparison to points further north. But then Baltimore itself tends to be more amiable than point further north. Good luck.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.