If only one way is selected (not downloaded from server, to reduce possible problems), you can redraw or re-simplify it by pressing T twice (T T). Unused points will be deleted when saving line (Enter-Enter). Beware - tags are deleted. Undo Ctrl-Z works. This feature can be used to simplify alternatively created ways (tracks etc.) or for resimplifying with different parameters.
Edit action list [no undo!]
Backspace - delete last added point.
Shift-Click - delete selected point or line fragment.
Dragging node moves it.
After deleting line fragment you can redraw it by mouse. Segment being redrawn id highlighted orange. Always draw from start to the end of line! To return to line continuation from this mode press Shift-Click not on nose or ESC.
Ctrl-Shift-Click - delete the whole line and start new one
Snapping to existing nodes, point fixation
When dragging and clicking near existing nodesm than nodes can automatically include in drawn line (they become fixed and are not changed by simplification). You can turn off this behaviour in settings (Q).
After clicking on starting line point you close the line, it can not be continued by mouse.
Ctrl-Click on existing line point - fix or release this point.
By using checkboxes in settings, you can force all nodes added by mouse clicks or Spacebar to be fixed.
Simplification detailed description
When Enter if first pressed, depending on settings plugin performs simplification with initial epsilon or autosimplification: while there are line fragments with 10 (fastdraw.pkmblocksize) points with PointsPer1Km greater then max PKM(fastdraw.maxpkm), detalization is decreased.
Initial epsilon value is given in screen pixels (fastdraw.startingEps), so the simplification depends on current zoom level.
Up/Down buttons multiply epsilon by configured coefficient (fastdraw.epsilonmult). Current line information is displayed in status bar.