Is the ill conduct her attitude when she contended cards or something else? I figured speaking up in Yumi's case is justified as long as she was right but if it's that attitude you're referring to then it's a different matter. As for the infamy I don't have anything since think it's open for interpretation which mean you could be fully right.
Just a question Chihaya's mental breakdown during the match, does that play any role in how you view Yumi?
I shall try and hopefully you'll try and answer the one question I've asked you twice already. Why would she feel guilty over contending for cards when we saw that the only two cards we've seen her contend for were rightfully hers? Again I don't understand why she should feel guilty about it other than holding up other peoples games, this is of course assuming she only does it when she's right.
Karuta as we know it through the show is based on poetry and as Kana said in episode 6 at 20:32-20:35 on the history of these poems "only members of the imperial court dabble in poetry" and that's what karuta has it's roots in. Is it ok if I draw the line imperial court = refined people? And this is a game based upon these people. Does that clear up how it has anything to do with Yumi dropping her usual playing style? It has nothing to do with her behavior or strategy as you say as it's nothing more than a theory on why it would be unfit for the queen to contend for cards and be so loud about it. But you are right Kana is fixated on elegance and refinement far beyond karuta as a game but that doesn't make the historical facts she mentioned are false. How much weight each player places on those roots will obviously be different some will care a little, some not at all and other will care greatly.
I'm not sure what else you want me to try and clear up so if there is more please do tell.