I'm sorry I'm late to the party, I haven't read all the posts so probably someone's already said the same.
Costume de Fete looks good on you. Just wear it with black and red lipstick. It's a party scarf, it's the life and soul of any party, but it needs to go to the party without competition.
Rather than go scarf by scarf, maybe work out what makes you really love/not-so-love certain scarves. I.e. which themes, sentiment, best colours, favourite artists etc. If that means keeping all Fetes Venitiennes and getting rid of every gav so be it (not a suggestion, just an example).
It does help to see you in scarves though. Design: (Only IMO) I think you look best in bold, luscious prints, even better with definite curves (in the design). I don't think you look as good in the ultra-femme, wispy, ditsy prints. You can take high-contrasts and complimentary colours too, and the stronger earth tones. Those greyed, low-contrast colours need strong lines to make them work.