Okay, a bit more details then, for others who may need the info in the future. This is, of course, from my point of view only, and I would say I have a pretty tight comfort zone when it comes to my son's FA. The info is also only for Malaysia, where we spent most of our time.
When planning the flight itinerary, I first chose an airline that did not serve peanuts as a complimentary snack to passengers (United). Next I considered the length of time flying over the ocean (vs. over land) as well as the location of the stopovers. I tried to minimize the trans-ocean legs and chose stopovers where it would be relatively easier to find safe foods in the event of an unexpected delay. Other than the drinks, I did not let my son eat the foods served on the plane.
While in Malaysia, we stayed in my parents' home. I'd given them specific instructions months in advance about 'de-nutting' the house and also asked my mom to buy me some new pots and pans. My mom was great about "getting it" for the most part so I felt comfortable cooking in her kitchen. For those who don't have family living locally, I would recommend renting an apartment or hotel with a kitchen. I went to the local market daily to buy fresh vegetables and meat to cook my son's meals. I'd packed with me some U.S.-made spices and condiments (bouillon cubes, instant gravy and sauces, etc.) Thanks to the British influence in the country's past, there are grocery stores that sell some food products imported from the U.S., Australia, and the U.K. The only local foods my son ate were the juices, fruits, veges, and meat.
I know some people are okay with carrying a chef card and eating out in a foreign country but even though I speak the local language, I do not trust the level of allergy awareness there to allow my son to eat food prepared by others. Certainly not in Malaysia where peanuts and shellfish are so prevalent in the local diet.
Lastly, I must say that the medical facilities in Malaysia are actually very good, considering it is a developing nation (and I'd confirmed this with our allergist here, as well as a doctor friend in Malaysia). Many hospitals also have their own ambulance service...I had all those numbers programmed into my cell phone, of course. I'm not sure I would have decided on making the trip if the country did not have medical services that could handle anaphylaxis.
All in all, I feel that I did what I could to minimize the risks to a point that was acceptable to me, but the reality is I could not eliminate the risks completely, so ultimately there was a step of faith involved. I did my part and trusted God to do His part to keep my son safe.
I hope all this will help someone else at some point. If anyone has other questions or would like additional info, please ask!
Irene