No, not if it’s been expired for a while. There’s a grace period where it counts as a renewal, after that it’s treated as a “first time” application.
Also, if you’re born in the UK as a dual national, you don’t have to ever get a British passport. I flew to Canada on my Canadian passport. There’s nothing stopping you from doing that.
Yes, but how do you get out of the country to live somewhere else without getting your first UK passport while you are still in the UK?
I’m not sure, but I think the requirements when you are renewing an expired passport are somewhat easier to meet.
No, not if it’s been expired for a while. There’s a grace period where it counts as a renewal, after that it’s treated as a “first time” application.
Also, if you’re born in the UK as a dual national, you don’t have to ever get a British passport. I flew to Canada on my Canadian passport. There’s nothing stopping you from doing that.