To limit the visible points in the 3D viewport :

- select all object/bones (A) and desacivate the motion Paths (easy Paths button)

- Select only objects/bones you absolutly need

- change the start and end frames in the timeline (or in the output properties)

…before reactivating the easy motion Paths button

The easy motions Paths is build to be as simple as possible. It create/delete motion Paths points with the easy Paths button. To delete all points, select all objects ("A" shortcut) or bones and clic on easy Paths button

In gtaph editor, you need to update evrytime due to the limitations of Blender's Motion Path module. But If you activate the Auto Keying and move your objects (G key) in the 3D viewport, see the objects Paths update in real time without the clicking on the update button.