Under New York law, only a Licensed Engineer can assess structural integrity, sufficiency of electrical service or heating, etc. An Inspector who is not an Engineer cannot advise you about structural soundness. If they do they are deceiving you and breaking the law.
Becoming a Licensed Engineer requires a minimum of four years of Engineering College and four years of relevant work experience with Building Codes, Engineering Standards, passing two 8 hour each Engineering exams, etc. A Licensed Engineer is also required to take continuing education to keep up-to-date for their entire career. A New York Licensed Home Inspector needs to take only a 140-hour class, which is the equivalent of one month of training.