You should use special names like "COCKPIT_DOOR_CLOSE" instead of display labels like "Cockpit Door Close". You also can't use special symbols (like [ ] { } \ ) in key names, they should be referred by their names.
That's why gecko said it is easier to use controls menu.
But here I fixed your list to save you some time.
Should be all as you set, except I had to modify gunsight controls because "{" is just "Shift+[". I don't remember if these match the old gunsight controls, can't check right now
<Key ID="C" Mod="Control" Action="COCKPIT_DOOR_CLOSE"/>
<Key ID="C" Mod="Alt" Action="COCKPIT_DOOR_OPEN"/>
<Key ID="L" Mod="Control+Alt" Action="LANDING_LIGHT_EXTEND_TOGGLE"/>
<Key ID="R" Mod="Control+Alt" Action="RADIATOR_SHUTTER_CLOSE"/>
<Key ID="R" Mod="Shift+Alt" Action="RADIATOR_SHUTTER_OPEN"/>
<Key ID="F1" Mod="Shift" Action="STARTER_COFFMAN_INDEX_KEY"/>
<Key ID="1" Mod="Alt" Action="BOTTOM_FUEL_COCK_TOGGLE"/>
<Key ID="2" Mod="Alt" Action="TOP_FUEL_COCK_TOGGLE"/>
<Key ID="3" Mod="Alt" Action="GENERATOR_TOGGLE"/>
<Key ID="L" Mod="Control" Action="LANDING_LIGHTS_TOGGLE"/>
<Key ID="4" Mod="Alt" Action="LANDING_LIGHTS_TOGGLE1"/>
<Key ID="5" Mod="Alt" Action="LANDING_LIGHTS_TOGGLE2"/>
<Key ID="G" Mod="Control+Alt" Action="GEAR_EMERGENCY_EXTENSION"/>
<Key ID="6" Mod="Alt" Action="GEAR_POSITION_LIGHT_TOGGLE"/>
<Key ID="7" Mod="Alt" Action="GEAR_WARNING_HORN_SILENCE"/>
<Key ID="N" Mod="Alt" Action="NAV_LIGHTS_TOGGLE"/>
<Key ID="S" Mod="Control+Alt" Action="STARTER_COVER_TOGGLE"/>
<Key ID="F" Mod="Control+Alt" Action="BOTTOM_FUEL_QUANTITY"/>
<Key ID="F" Mod="Alt" Action="PARACHUTE_FLARE_RELEASE"/>
<Key ID="LSquare" Mod="Shift+Alt" Action="Gunsight_Brightness_Decr"/>
<Key ID="RSquare" Mod="Shift+Alt" Action="Gunsight_Brightness_Incr"/>
<Key ID="LSquare" Mod="Control+Shift" Action="Gunsight_Size2_Decr"/>
<Key ID="RSquare" Mod="Control+Shift" Action="Gunsight_Size2_Incr"/>
<Key ID="BackSlash" Mod="Shift" Action="GUNSIGHT_TOGGLE"/>
<Key ID="LSquare" Mod="Alt" Action="Gunsight_Size_Decr"/>
<Key ID="RSquare" Mod="Alt" Action="Gunsight_Size_Incr"/>
<Key ID="A" Mod="Alt" Action="GUN_SAFETY_TOGGLE"/>
<Key ID="S" Mod="Alt" Action="PRIMER_KEY"/>
<Key ID="M" Mod="Alt" Action="AUTO_MIXTURE_SETTING_NORMAL"/>
<Key ID="N" Mod="Alt" Action="AUTO_MIXTURE_SETTING_WEAK"/>
<Key ID="X" Mod="Alt" Action="SLOW_RUNNING_CUTOUT_KEY"/>