But, the act of faith in God to believe that the divine healing or act would occur is the key- obedience to God’s command not worshipping an object.
The serpent- “looking upon it ( in faith)” believing that God would forgive and heal, not loving an object. Pretty certain that those who refused to look upon the bronze serpent in faith , even though they were in proximity, didn’t survive their snake bites. Faith, not the object.
Namaan the leprous Syrian general, was upset that the prophet would not perform some miraculous deed, but rather was told to dip himself in the Jordan seven times. Did the water hold any power or was it obedience to the command of the LORD? If you think it was the water- you missed the Living God a ways back!
All of your examples are based on acts of faith- I would tend to think that if Namaan and all the others in these ( and your) examples did not believe that God could and would heal them, they would have gone on in sickness and handicap.
Did not the scriptures say that Jesus could not perform miracles in his own town because of their unbelief? Wow, if the Son of the Living God was prevented from direct action because of unbelief, then how would a mere object of created material have any power (sic)?
Aaron's rod that budded was not said to perform any miracles. The dead man who revived upon contact with Elijah's bones, by definition, did not have faith.
My point was, God chooses sometimes, even within Scripture, to work through methods other than those approved by 20th century middle class evangelical churchians.
The relics (I'm talking about the true ones, not those made by frauds) and prayers for the aid/intercession of saints, fall in the same category; if He chooses to employ certain channels (in the marketing term) to extend His grace, and mercy, that's His business. We ought to be grateful for whenever and however He makes Himself available to us.