Akarin should join in since she's always gonna be a third wheel anyway. And yes, Ayano x Kyoko is 10,000% canon, 100,000% romantic OTP, and they will get married. Yui and Kyoko have a very beautiful eternal bromance, same with Akari and Chinatsu.
I guess she has the worn down weird thing she wore in the beginning, and the big poofy dress, but she likely doesn't have them anymore, the school uniform is the only thing she still wears/has I think Rina, I'm surprised Cocona didn't make a narrative comment about it haha