I would say to go on the flight but be prepared just in case. Have an epi pen with you, Benadryl, whatever you need to recover when the reaction hits. You could even wear a mask if the people around you are eating peanuts. For me i would go ahead with your trip and not let the possibilities stop you from living your life as you want.
I have used Evolution in the past. It was very Outlook like and did a decent job talking to Exchange. Now days i just use the web interface.