Answer:
I begin your sentences.
My full powers come when my makers are dead. I await a heavy hat to put on my head. What am I?
I have a strong affection for belly buttons.
Travel a mile and I will change, travel a million and I will end as I started. What am I?
What word has kst in the middle, in the beginning, and at the end?
I go in hard, come out soft. Blow me hard and I'll make a pop. What am I?