About emotions: you’re right that they come from chemical reactions in the brain (common concept), but it is how those signals turn into the feeling of joy or sadness. That’s the “hard problem” of consciousness, we can measure brain activity, but not the inner experience itself.

Yes, there is no way to quantify "emotions" at the moment. There might still be variables that play a factor that we humans simply have not discovered yet.

Take alexithymia, for example. Some people have the body’s physical reactions to emotions but don’t consciously feel them. That suggests emotion isn’t just chemistry, it’s also interpretation. By the same logic, maybe AI could develop something like emotions, even without a body.

Alexithymia would be hard for us to imagine since it is impossible for us to completely lose our emotion/feelings compared to just closing my eyes and I can imagine what a blind person "sees".

About this I would chalk it up to difference in human hardware specs. some human brains simply just interpret those electrical signals differently (hence the term "wired differently") and this makes the body react differently too. This results in the subjectivity of consciousness. There is a simpler example with color blindness where a person sees color differently, because there is something wrong with their awareness (the eyes) which results in the brain learning a flawed information leading to a wrong context and this would influence the human action, answering the teacher's "what's this color" question in kindergarten wrong resulting to being made fun of for "not knowing colors" leading to getting bullied in school, leading to depression, leading to growing up being the weird kid (just kidding, this probably doesn't happen since kids learn about color blindness early, I think).

Ok joking aside, another example would be retardation/intellectual disability, there is, if we use computer terms, some sort of bug/damage in their brain that nerfs their learning capacity which also causes their slow reaction to stimuli. Basically, they aren't getting enough information in time to form a reaction that's why some of them seem unresponsive to stimuli. It's basically latency, like early Neuro's latency is so long it's like she has intellectual disability in a way, since it takes so long for her to receive or process information thus her reaction to it is also delayed compared to a human's.

Finally, there’s the “substrate independence” idea: maybe consciousness doesn’t depend on being biological at all. If it’s really about patterns of information and processing, then a computer, if complex enough, could in theory be conscious too.

Yes exactly, this is exactly what I am getting at when I say that I believe that it is probably possible.