All of the asked situations are now supported in iOS 15
Destructive: (works from iOS 15)
Set .destructive as the role argument of the button:
Button(role: .destructive) { // 👈 This argument
// delete something
} label: {
Label("Delete", systemImage: "trash")
}

Disabled: (works from iOS 14.2)
Add .disabled modifier to the button.
Button {
// call someone
} label: {
Label("Call", systemImage: "phone")
}.disabled(true) // 👈 This modifier

Divider: (works from iOS 14)
Use a Divider() view directly.

Full Demo:

⚠️ Remember! Do not use image instead of systemImage for showing an SFSymbol on the button!