You're starting the jitters early. It was only half way through the four hour flight from Singapore to Davao that I started to doubt my sanity. But then I did it twice more, at 2 month intervals, before my latest arrival in Phils back in December.
Her father was not at all angry, despite the fact that I'm only a couple of years younger than he is!
Now, 16 months on from that first visit, life is great, we have a wonderful marriage, and a baby on the way!
Butuan should be relatively safe ... it's about as far away as possible from the main area of hostilities, while remaining on Mindanao.
The main thing to look out for is everyone expecting you to be so rich that you can afford to just give your money away! However, your girl should protect you from this.