For B-splines / Catmull–Rom: click a control point to select it, then delete/move it.
Zoom: 100%
No curve selected.
Controls
• Drag empty canvas to pan
• Click a curve to select it; click empty background to deselect
• Drag points to edit; drag the curve itself to move it
• Zoom: mouse wheel (cursor-centered), or buttons
• Delete: Delete/Backspace removes selected curve