Blackbutterfly,
First of all, let me say that you are pretty brave coming here asking for advice - anyone IMHO who generally wants advice about a situation and does so on a forum, is pretty brave!
I can't get into whether you are mature or not - I don't know you well enough. However, I would advise a couple of things, being in the situation you are in right now...
1) Talk to your parents. Just don't assume WHY they are 'hesitant' but find out. Be respectful in these discussions and find out what worries them about it. If they are Christian, have a solid prayer time with them and your fiance about these 'issues'. Ask them what you can do to ease their minds, and see if any of that is possible. Believe it or not - some times this DOES work!
2) Talk to your minister, or the head of marriage/premarital counselling in your church. I am sure that they will have a questionnair like PREPARE that they can go through with you and discuss things with you that comes up out of it. If nothing is available where you are to discuss topics with an older married counselling couple, head to somewhere like Relationships Australia (I'm sure there'd be something like this closeby to you). Even if you think you've got everything covered, it's amazing how much a course like this can uncover!
3) Find an older woman who is a Christian, and has a military husband. Having someone alongside you as you're 'finding your feet' with being a 'posting widow' will help you SO much - they have been where you are, and can be a great friend when your hubby is off serving, and you're missing him like crazy!
4) Find some good married couples that are Christian and you respect, and see if they are willing to mentor you. I'm hoping my bf and I can find a couple like this willing to do this, when we get engaged. It is always good to include others who will support you and keep you accountable, and minister to you during this tricky adjustment times.
Like ITF said - Boundaries in Dating is GREAT! I also found a good book called '50 questions you should ask before you get engaged', or something like that (can't remember) - has a heck of a lot of good questions that you and your fiance should be going through before getting married. I also REALLY liked the books 'Every Man's Marriage' and 'Sacred Marriage'.
Military life is a HUGE adjustment, when you get married. My cousin is married to an ex-military guy, and although he never went on active duty during his work there, it did cause a lot of stressors on their marriage, and the only way she got through it is because she had an older married woman on the base who she could talk to when the going gets tough. Never underestimate how good someone like this can be for your marriage!
God bless you and I hope everything works out well for you!
Sasch