Hi James,

>the option to auto-trim that intersection

You can use the extend command, then select the two lines segments and right click two times.
It works if they cross or not.

There is a script for hiding all curves:
script:moi.geometryDatabase.getObjects().getCurves().setProperty( 'hidden', true );

(You go to options, shortcut keys, and put the line in the command section)

Marc