The Man's marriage checklist...
1) Get Married
2) Enjoy Honeymoon
3) Wait to Die
But seriously...
If you're a young pilot, be extra-cautious about jumping into marriage. The fact that you have to have special criteria for your spouse is just one more hardship imposed by aviation.
If at all possible, wait until you get the dues-paying mostly behind you, or at least to a point where most of the variables are behind you (ie hired by a major airline). No it won't hurt you to wait until you're 35, you'll still have 50-ish years to enjoy matrimony. If you're worried about re-productive issues marry a girl who's a few years youger.
Don't marry an American woman younger than late twenties unless she is truly exceptional in her maturity. Most simply have no idea what they want long-term and will change you like a flat tire once they figure it out.
I have mixed feelings on pre-nups. Personally the whole thing would tend to poison my sense of trust for my spouse, but that's just me. Probably best to do one...I don't think it will get you out of child support, but I think it can protect any assets you brought to the marriage, and post-marriage income.
If you already have assets and a pre-nup is a bridge too far (I would be hurt if asked to sign one) you can always but your stuff in a trust. Of course she'll have to know about that eventually. If your parents have assets, make sure they put your inheritance in a trust for you.