I love this pair :) And I'd say there was SLIGHTLY more yui x kyouko in the 3 summer eps but only if you wore yuri goggles - Yui is ALWAYS embarrassed and blushing over ANY emotional displays and the like - and Kyouko is ALWAYS making jokes and teasing Yui - but it is always clear she is joking - she just loves getting reactions from Yui.
I still saw none of their interactions in those summer eps as more than good friends - one who likes to tease, one who gets embarrassed easy.
Whereas Ayano 100% clearly is in love with Kyouko - it was clear from season 1- that IS cannon. Sadly it's also 100% true that Kyouko is clueless and just sees her as a friend atm. Which is why I love to see them get together in doujins or pics :)
Its a shame whoever you ship we will almost surely never see any of them hook up in the show / manga.