I hope this is the right place to share some Achievement ideas I have. I don't know if everything is possible but those are things I believe would be fun to have:

I spit on you - One Spitfire kill
I double/triple spit on you - multiple kills with the spitfire within a short time
Don't spit on me - Death to a Spitfire
Pixel Perfect - long range headshot kill (+70m) with anything but Bolt Action Rifles (and maybe semi-auto Scout/Battle Rifles)
Disbanded Fireteam - 3 kills of different players from the same outfit without intermission
Disbanded Squad - 12 kills of different players from the same outfit without intermission