Strictly no. Essentially, yes.
Perhaps. Certainly they are the source of endless debate.
You missed the point. I am not at the same size, weight or state of development as I was yesterday, yet I am the same person. What I am remains the same throughout these changes: I am a human being. My nature, essence or substance remains the same while my "accidental" characteristics may change.
There are many points. That's why the debate is so voluminous. That you are essentially the same today as you were yesterday is a far different discussion than are you the same today as when you were a one cell fertilized egg. Hence my initial question: is an egg a chicken? Is a caterpillar a butterfly?
Does your essence change when you become dead? I'm guessing you'd say it does. So where is the point of death? What changed? Is death a moment in time or an interval of time? If an interval, however short, does your essence change between the first part of death and the last part? It must.
I'm not bring these things up to be trivial or to divert the discussion, but to establish that there are difficult concepts involved. To pretend that the debate around abortion, by either side, is simple is to pretend.