#1
I recently visited my daughter, a Peace Corps volunteer, in Panama. We spent five days in the Darien jungle where we both received hundreds of flying insects bites all in about 20 minute timeframe that our Embera (indigenous people of Panama) guide said were from "morongoi" flies. I tried to identify these insects via google searches but was unable to find anything definitive. I see you are a dipterist who hosts the diptera.info.net web site) Have you heard of these insects? There are hundreds of species of diptera in Panama so I thought I would ask for help. Perhaps you can refer me to someone in Panama.
#2
Can't help with that particular name, but it does sound as though you were the victims of sandflies (Psychodidae, Phlebotominae). Never been to Panama, but accounts I've read suggest that sandflies are up with mosquitoes as the major pests there.