My two cents;
Air Strike - could be acting as either a pilot or Forward Observer
RaidingAmbushMeeting Engagement - when two sides (usually armoured) slam into each other while on patrol.
hmmm
Patrol fighting patrol or recon
Tank Hunting - possibly covered by Patrol. A unit locates an enemy armoured unit's lager or refueling area.
Amphibious AssaultRelieving action not sure how the military would term it. Basically battling through to an isolated outpost
Escort - a convoy otherwise it's just a defend mission
Sniper - either assassination or operating on the flank of an assault.
Deception/DiversionHow about manning checkpoints? Might need to check on this but I think that would come under a Saturation Patrol
Insert & Blow up
how about
Asset Denialedit:
Not sure if Guerrilla warfare would have it's own terms but
Hit and RunAsset Acquisition - stealing equipment and vehicles
edit 2:
Thought of some others
SabotageEither destroy something or I always wanted to make a mission where one of the objectives was to "poison" one of those water towers on Sahrani.
Escape & Evasion Escaping custody
Prisoner/Hostage Rescue Intel Gathering Computers, most missions I ever plan out have the player hacking a computer somewhere but can just as easily be rifling through a desk or reading cargo manifests on trucks or crates
A mission can have just one of these facets or combine several of them. I planned out this mission a while ago and like so many others I never got around to finishing it. Infiltrate an enemy base (Stealthily - mission changed if spotted) and place a tracker unit in an enemy ammunition truck. Then using a tracker script, follow truck to main supply depot and blow it. Has a little of everything.