Just flipping in my pair o' pennies on the Claire/Emily/Gabby thing, I don't see any problem with their introduction, or how it's gone since. I mean, yes, this is a story, and stories are generally driven with a particular sort of context, in the sense that if someone is introduced quite noticeably into the fold, it means you'll be seeing more of them.
But in this case, and it's been this way for most of QC, too, it's more realistic. In real life, people come and go. Sometimes you'll meet a group of friends or co-workers, and only one will gel, if any. Not everyone enters our lives to be there permanently. So removing skin color/race from the equation (not as a form of erasure, but just to look at this picture in a more general perspective) I get what Jeph did with Gabby, even unintentionally. She might not have ingratiated herself into the complex web that is our long-beloved main characters, but that's absolutely more than likely because she's living her own life with friends, family, etc. off-panel.
As for Emily and her quote-unquote "weirdness", I think it's just a case of Flanderization more than anything else. But this happened with other characters briefly too; one could argue Faye's first punching of Marten, then leading to her being almost notoriously violent for a time, was a form of Flanderization, but that's since been long gone. Point being, if Jeph expands on Emily's character, he expands on her. If she doesn't, I don't think we should take it as a form of racism or tokenization or anything negative like that; we should just enjoy her for what she is, that being a weird, lovable gal who doesn't have a lot of hangups about how people see her, and just goes on her instinct, asking and doing things other people perhaps won't.