You raise some very thought provoking points that are a great starting point for discussions about miracles. Faith is essential in our relationship with God. Hebrews 11 not only defines faith, but describes faith in action in the lives of those who were led by God.
I agree that many miracles that Jesus did hinged on the faith of the receiver. Some miracles it seemed depended on the faith of someone on behalf of the receiver. I am thinking of the four who carried a man to see Jesus and could not enter the house. So they tore the roof off and let their friend down into the room.
We have been studying the miracles in the Gospel of St. John. John's gospel sums up the purpose of the miracles that He wrote about in chapter 20 verses 30-31 "Many other signs truly did Jesusin the presence of his disciples, which are not written in this book. 31. But these are written, that ye might believe that Jesus is the Christ, the Son of God, and tha believing ye might have life through his name.
The purpose of Miracles, I believe, is to cause all who see it and hear about it to to exercise faith in Jesus as the Son of God and trust Him for salvation.
Thank you so much for your post. Blessings and peace