ERCP 

No

Almost no, for most of the gallstones come from ur gallbladder, although still a small part of them from the liver.

No

I was told yes, not super common but can happen. Thinking it has happened it to me.

Yes it happen to me after my gallbladder removed, I had bad pain in my Back and upper stomach, I went to emergency they do CT scan and after they found stones in the region of the gallbladder. And than my doctor ask me to the MRI to see more details about it, I m still waiting to see what I have to do, really painful 😢