You are probably going to get a few nasty responses along the lines that "you should never use the word "astrology" in the same sentence as 'astrophysics' or 'astronomy.' Doing so makes quite a number of people angry.
The length of time it takes to get a Ph.D. depends entirely on you. I know of some one who just went to his fifth high school reunion in New Orleans who has just moved to Berkley to start on his Ph.D. I'll have to check with his mother whether he has two bachelor's degrees and a master's degree from Stanford or just one bachelor's degree and a master's, but he did a lot of work in engineering and physics as well as what is best described as classical studies.
Speaking as a graduate student of many years in geology, energy companies often send representatives out to college campuses to conduct interviews and recruit applicants. The department would put up sign up sheets on bulletin boards for any one who wanted to interview with a particular company three days to two weeks before the company representatives were scheduled. Companies and universities often send notices of employment opportunities to other universities and colleges. A lot of those notices probably are electronically posted now, rather than on bulletin boards. I can't speak from personal experience, but most astrophysicists usually are associated with either a university or a research institute in some way, even if they technically work for the federal or state/province government. There are many online job/resume listing services of all types, from the huge ones like monster.com and usajobs.gov, to specialized boards like GISjobs clearinghouse (http://www.gjc.org/) that was started by the University of Maine in the mid-1990's, to individual university employment opportunities (look under human resources).
You have plenty of time to decide what you want to specialize in and what order you want to do it in. You already have an open mind, and you want to learn new things. That's all it takes to be a true perpetual student. Remember, "when you become a teacher, by your students you will be taught." That is certainly true, as I've been finding out for the last 8+ months. Most likely the biggest problem you/your parents will have is how to pay for it. ("If you think education is expensive, try ignorance" may be a cliche, but it is also quite true, as the breaching of the east flood-wall of the 17th street canal made quite obvious to the rest of the world on August 30, 2005. I knew the 17th st. canal was a perfect textbook example of conditions that would eventually lead to the geological fracturing of the east, not the west flood-wall, although the west flood-wall is STILL "bent", if and when the right weather conditions existed more than 11 years and 8 months before it actually happened.) I know I was fortunate enough to be the daughter of a Tulane University faculty member, so my tuition for Newcomb College and two of my bachelor's degrees was waived within the university, even if it did take months for the financial aid forms to get from one campus to the other (this was 1971 to 1980, pre-PC revolution). My dad paid fees and dormitory fees, but I got a ten per cent discount on text-books at the Tulane bookstore. When I went to the University of Oklahoma in January, 1981, I was charged out of state tuition for a year until I established Oklahoma residency. Than I got an teaching assistant-ship with the School of Geology and Geophysics for two semesters, so I was paid a nominal amount for supposedly working twenty hours a week teaching two physical geology lab sections. Because of health reasons, that master's degree (in geophysics) was aborted. I was out of school for seven years, then went back as a special student in the fall of 1992. I thought I know exactly what I was doing in the fall of 1993 when I became an undergraduate for the third time to work on a bachelor's degree in physical geography. I had no idea that over the next 10 academic years I would get a very good education in the politics of how a public university really works. Tulane University, since it is private, operates in its own little universe, but faculty meetings have just much yelling going on at both public and private universities in the USA. I got a lot more informal eduction in life at the Universities of Arizona, which I usually leave off of my resume, and Oklahoma than I ever did as a sheltered undergraduate at Tulane, even if I did reside in graduate student dormitories when I lived on campus. As an example of how sheltered I was, I didn't get my first driver's license until I was 24 years old in 1977.
