Earlier this year I did a 2 month trip all over Mindanao and I can never remember being either abducted, raped or chopped up. We visited big cities, small cities, small towns, remote mountain villages and on the whole found nothing but friendly welcoming people. Admittedly we didnt go to Zamboanga, but we did pass through areas that I would consider just as sensitive. What we did do was to carefully research online exactly what was happening locally, and did find a few shootings, bombings, kidnappings etc in some of the places we were about to visit. But we decided that would probably not affect us, and it didnt. I would firstly carefully check with local news online to see exactly what has been going on recently in Zamboanga and then make a decision. Another factor to consider, is that if your home country has a travel advisory against going there, then almost certainly you will not have valid travel insurance. We knew that but it didnt stop us going and we had an awesome time in Mindanao..