Probably the reason you have had no other replies is that most of the people on the forum are N. Amerca based.
I do not share your frustration at all about this subject not having any desire to go through the agony of solo performances.
The only two competitive festivals I know anything about are Abingdon & Oxford & they are geared more towards the junior end of the spectrum although there are some open classes with no age limit. Even the British Flute Society appear to only do events aimed at the younger players.
God luck with your hunt for other people to play with - it is difficult for flautists as there are so many of you fighting for available seats. You ought to play contra bassoon, bassoon & bari sax like me - playing oportunities are much easier to come by.