Maybe this can help you :)

H ----> hide invert selection
I ----> Invert selection
Space----> object visible : Select all / Deselect all
(if letters are not used for other shortcut else just change the letters)
And at last you can use the icon "Hide" when you are lost :)

you can add folowing (3 lines)
in the .....\Application Data\Moi\moi.ini in section
[Shortcut Keys]
H=script:moi.geometryDatabase.invertSelection(); moi.geometryDatabase.hide(); moi.geometryDatabase.selectAll();
I=script:moi.geometryDatabase.invertSelection();
Space=script:var selection = moi.geometryDatabase.getSelectedObjects(); if ( selection.length == 0 ) moi.geometryDatabase.selectAll(); else moi.geometryDatabase.deselectAll();

Have fun combinatory selections :)
Very powerful before some system of manage objets :)