I was meh about Debbie until the Cousin Patrick story. After that, I felt like she really fit into the family. I think this current storyline could really make her character, so I'm taking a wait and see approach. Mickey is a great character, in many ways, better than Ian, imo. I love the humor of the show, but I also like some of the seriousness. As someone who has BPD, I've been hoping for a little more from the Ian storyline, but I guess it can be a little difficult walking the fine line of levity and seriousness. And I still like Fiona, I just think she needs a little time on the backburner instead of always being in front. They're wearing the character out that way. One of the reasons Frank has stayed fresh is because even when he's involved in a storyline, he doesn't always have to carry it. He just kind of floats in and out.
I think we eventually see Sheila again. The way she left made me think she'll be back at some point. Not so sure about Jody or Karen, but I'd be willing to bet Sheila makes an eventual return, but probably not this season.
And call me crazy, but I'd love to see Chucky return and have a face off with Carl, lol. Sammi can stay gone, but I think Chucky's kind of funny.