A few things to keep in mind (this coming from someone who has survived the rigors of a BS in Chemistry).
1. If you want to be a glorified mechanical engineer who knows everything about flow rates and practically zip about chemistry who makes craploads of money with just a BS degree, go into Chemical Engineering. If you want to do actual wet chemistry and get nothing out of your degree until you have a PhD, go into Chemistry.
2. Engineering definitely has more job opportunities, but the higher a degree you hold, the less marketable you are. Chemistry is the opposite.
I took chem, AP chem, and a qualitative analysis and organic chem class in HS. Our high school was fortunate enough to have such a class. I loved phyics and math as well in HS, and thought about going into these until I got into AP chem. I actually was better at both physics and math than chem, but liked the chemistry better. I still struggle with chemistry today, but I love it. Go with what you love.
In terms of Gen Chem in college, if you've got a year off between your last chem class and your first year of college, I would take Gen Chem in college and not try and skip out on it in lieu of the AP exam. It will be somewhat difficult, but it is also geared for those who have taken very little chemistry in HS as well, so you'll probably be OK. If you want to read up on some chemistry, take a look at Zumdahl's Chemical Principles. It's the most widely used general chemistry book in first year college courses. You might also want to see if you can sit in on night classes at your local community college, just audit them, if possible. They might not have a problem with that. Of course, you can also just read up on some books yourself in your spare time (which is not much if I remember my HS days well).
Another thing to do is to go to a college with a chemistry program and ask to talk to some of the graduate students in chemisty and see their research labs. Then take a look at the chemical engineering labs and see which you like better. Just remember to visit organic, inorganic and physical chemistry labs--they're very different. Best of luck, and if you have more questions, drop us a line.