The grass is always greener?....as I look at your situation, I don’t believe - in the long run - that becoming a captain/instructor will provide you financially with what you might be expecting...there’s a lot of competition out there and experience will not be in your favor. Your passion for diving and the infatuation for this life may quickly lose it’s luster...then, as you said, where’s the next job offer going to come from? Do a lot of soul searching and gathering facts from those who have done this before before taking that "giant stride"!