I have a like... super rough, loose, vague timeline of everything that's gonna happen. I know, in the most general sense, the basic path the story will travel, what the protagonists are doing, and how the story ends.
So like, on a "they go to the emerald city, they're captured by the witch, they defeat the witch, return to oz, unmask him, the wizard fails to take dorothy home but she learns the shoes will do it, returns home" level of detail.
The story is divided into 3 parts, and I have the basic beats of the first two parts written out. So like, part one is chapter 1-5, and I had all the major scenes for each of those five chapters written out; part 2 is chapters 6-10, and for each of those chapters I have an outline of each major thing that's supposed to happen, and then I have a vague idea of what each chapter will be about in part 3.
I want to have all the scenes for the chapter that's coming up figured out, and I want to have it fully scripted before I start on it -- so either I'll script the next chapter while I'm drawing this one, or I'll take a break after this chapter to script before I start the next one.
I don't intentionally plan ahead much more than that. Obviously I'll randomly get ideas sometimes and figure out how an entire scene in Chapter 10 should play out when I'm still on Chapter 3, but I'm okay just having a rough idea of the things that will happen in Chapter 10 and nailing down the specifics when I get closer. I don't want to forget important stuff, and I do want to know like, where the story is going so I can do all the proper set up and stuff, but it also helps me to be excited about the story if it's not ALL planned out in advance and I have some wiggle room to discover details and fun scenes when I get there.
Not usually? Like, if five hundred people are like "oh boy I hope X happens!" that does not have any bearing on whether or not X will happen, because the story itself is my story, not a choose-your-own-adventure. But like, if someone suggests a theory about something in a character's backstory or something and I'm like "yeah that actually fits really well" I might adopt it and it might show up in the story as true.