I would rip out every tiny mistake I ever make. I'm anal that way. But I wondered what others do because I know what I do is probably a bit much. I posted before about how if my seams are off, even when I have to put my nose an inch away from them to see them, I will rip them out. I'd prefer not to waste so much time doing that but it's hard for me not to.
With tucks it's between having at tuck in there or obvious stopping and starting of a quilting line. Unless I rip out the entire line of stitching, which I also have done. I've ripped out quilting which took an entire small spool of gutermann thread before. That sucked.