Realizing that your turning from their church will cause a rift with your parents is very important. A question you have to ask, and try to guess at the answer, is would it be better to talk to your parents about having them loosen the reigns a bit now that you are 18 or is it better to not ask. Only you can decide what to do but think it through carefully.
These are certainly reasonable things for you to do but realize that not all teenagers are allowed to do these things and being a JW has nothing to do with it. I knew kids growing up that could not date, could not socialize without a parent, nor could they hold a job. They were not JW either. Once they got into their late teens the restrictions were lifted somewhat. Parents put restrictions on kids for a variety of reasons not always religious. At 18 you should be able to do what you have listed as far as I am concerned but I ain't your parents.
Your problem is simple. You are 18, a legal adult, dependent on your parents, yet not liking their rules, and wanting to have some freedom. Nothing wrong with that at all, and from what you have said, I think your parents are too restrictive. The solution to your problem is not simple. Since you do not have a means to support yourself you have to accept your parents rules or find a means to support yourself. Joining the USAF will allow you to escape your situation but will the AF really help you reach the goals you have set for yourself? Or should you suck it up for a couple of years and get the training and certifications you have lined up? The third choice is to talk with your parents, but you seem to think that could be a problem, and it may be depending on how you approach the conversation. Those are NOT easy decisions, but being an adult means having to make hard decisions, and living with the results.
Can you approach you parents and ask about getting a job now that you are 18? I don't think you should ask them all at once What you are requesting is more than reasonable, but from a negotiation standpoint, start with the most reasonable request.
If you cannot talk to them about this situation, then you are back to living with the situation until you get your certifications or joining the USAF. Those are the two options you have outlined.
The word "scared" and "talking" can have many meanings. If you cannot talk to your parents, can you write out what you wish to do, and why, instead of talking? You are very articulate in writing, and I think you could make an excellent case for getting a job. A note is less confrontational and provides TIME for YOU to put down all of your arguments in defense of your position and provides TIME for them to absorb what you said before THEY respond. Having these types of conversations can be stressful, which can lead to things being said, that should not be said, and things that should be said, being left unsaid. Writing them out can make things a bit easier.
Stand back a bit, and realize that what you are dealing with is a PITA, but not the end of the world. What you are doing is prepping your way to be an adult and you have a good plan. You are MUCH farther along than most 18 year olds. You have outlined a couple of different solutions to your problem. Both are reasonable but maybe not perfect. Life ain't perfect. At least your parents DO care about you. I have known plenty of kids whose parents have not given a rats behind about their kids.
Later,
Dan
Thank you very much for the idea about writing a note. I really like that and think it would be better. I'll think about it.