I have been a law enforcement officer for over 20 years and I don't think I would be happy doing anything else (at least not that I could realistically earn a living at). It is both rewarding and frustrating depending on the day. I can honestly say that there are people alive today that would not have been were it not for my direct intervention and that is something that few professions offer. But by the same token, I have 6 friends whose names are carved on a wall in Washington because they were klled at work, 4 of them were murdered, not many professions offer that either. It is not the gllitz and glamor portrayed on tv however. It is odd shifts, long hours, often under harsh environmental conditions, it is missed holidays and special occasions, it is interrupted plans, I guess what I am saying is that it becomes more of a life style than just a job. It is not for everyone and those who only do it for the money usually don't last long or don't do a good job. Also it will change you as a person, you can not deal with types of things you have to deal with and it not affect you, so you have to be on guard to deal with that. Also since you are already married, it will be an adjustment for your wife as well, it takes a special kind of lady to be a cops wife.
Now as far as feeling like my life is in danger daily, I really don't, I accept the fact that any contact I make may go bad, but you just have to accept that use good tactics and go on otherwise you will go crazy. I am not saying you wont get into situations where you experience fear because you will, you just have to work with the fear and drive on, you can't let it rule you. As a police officer you can't just walk away from a bad situation, you may have to fall back and wait for help but you eventually have to deal with it.
If you want to work for the KSP now is an excellent time in that there are a lot of vacancies, go take the test and see how you fair. As far as the FBI goes, I don't know if they are hiring many now or not but if you choose to work for them plan on moving every few years for the rest of your career.
My comments were not meant to discourage you because I absolutely love working in law enforcement everyday is different, I have worked patrol, drugs, special operations, and K-9 where else can you get that kind of variety in your job. If you have questions I will be glad to answer them if I can.