Answer:
What is so delicate that even mentioning it breaks it?
I start in little but I end in full, you'll find me in half and complete.
He's small but he can climb a tower.
Built of metal or wood to divide. It will make us good neighbors, if you stay on your side. What is it?
What Botox will do to your expression.
People take me on walks and I run and have fun. What am I?