Daisy was hard for me to type. I'd at first pegged her as an ESFJ, but I can't imagine her being Fe dominant. Then I put ESFP, but after seeing your type I can see where she might also be using Ti. I get the ideas and possibilities thing, but she always seemed too materialistic to be N-dominant to me.
For Rube, punctuality is definitely his thing and he does like closure, but I saw more Ti than Te. I can see him as an IXTJ actually, thinking about it more.
Joy, not likely an extrovert, agreed, though not really that introverted either. At least not to me. She seems to outwardly emotional to have tertiary Fi though. I can see ISFJ, but not really ISTJ. I pegged her initially as an extrovert because she was always so opposed to Reggie never having any friends and living in her head all the time, which for an introvert seemed odd to me.
I can see Mason as an SP, and he always came across that way to me, except when he was trying to explain himself for things. While not that convincing, his excuses were always very imaginative to me. Plus he idealizes the girls he likes (Daisy, Charlotte), to the point where I can pin the image of a wounded idealist on him.
As an afterthought, does anyone else find it amusing that Betty was doing a temperament test on Mason, and then consequently a dead guy, early on in the show?