Can you change lines from 'Model lines' to 'Detail lines' without having to delete them & redraw?? I tried using the 'Match Type' button but it wont work also 'Linework tool' . I mistakenly draw a stack of lines without realizing they will show up on other levels, I can hide them in each view but is time consuming

i dont think you can change the model line into a detail line because revit uses families and a a model line is a different family to a detail line.
The same reason you can change a wall into a door.