Fighter guys are gone less than just about any other pilots, and their job is a heck of a lot safer than most.   But then again this is coming from a spec ops pilot so take it for what it is worth.
And the "only real reason" to want to be a military pilot is to be off hacking the mission, so if you do not want to deploy a lot, then do not bother becoming a military pilot, we do not want you if you have that attitude.
Your wife will have to get over it or else it will strain your relationship.  The chances are that she will have trouble at first but then learn how it is different being a military wife and the relationship will be fine.
There are much more dangerous jobs out there than being a pilot so your girlfriend should not worry. And married life is married life, the big difference with military married life is that it will be much easier in the beginning if you both understand that you are in for more trials and tribulations that most people but also more dignity and belief in a good will towards life.
 IT IS IMPERATIVE THAT YOU HAVE A STRONG RELATIONSHIP BASED ON SOME TYPE OF FAITH, and by this I do not mean religious faith.  It could be religion, it could be in family and children, it could be in an adventure to explore then world when you are together, or it could be a faith serving the community and society.  But above all you need to have faith in more that just the typical "we love each other so much, and its just right with us, its different" because the truth is it is not different.  It is a lot of hard work that in my humble opinion is worth every second and more.

Good luck to you in all your decisions and adventures,

P.S.
Don't be a dickhead, nobody likes a dickhead, and there are other better ways to get things done.