For those who like such things, herein I'll define my terms (somewhat):
Medal/Label name (icon) - trigger [value(s)]Structure Destruction (red or blue "S", depending on which team you are on; Arabic numeral superscript for multiple occurrences) - for destroying an enemy structure within the last 30 seconds [51% damage]
Double Kill (bronze, silver or gold Arabic "2", for 1st, 2nd and 3rd-plus occurrences, respectively) - for killing two enemies with one grenade or within X seconds of one another [range of possible max.: 3-15 seconds]
Multi-kill (bronze, silver or gold "M" for 1st, 2nd, and 3rd-plus occurrences, respectively) - for killing 3 or more enemies with one grenade or within Y seconds of one another [max range as above; different value than X]
Killwhore (black "K") - for killing Z enemies without doing A damage to enemy structures within B minutes [e.g. - Z=10, A=100, B=3]
Decon (green "D"; Arabic numeral superscript for multiple occurrences) - for deconstructing any structure of your own team, whether as a builder or with a weapon/attack, within the last 30 seconds [51% dmg or builder deconstruct]
Teamkill (orange "Tragedy" mask with devil horns; black Arabic numeral overlay, for multiple occurrences) - for killing a teammate within the last 30 seconds [51% dmg]
RC/OM Destruction (bronze, silver or gold crown with white halo, for 1st, 2nd, and 3rd-plus occurrences, respectively) - for destroying the enemy main structure within the last 30 seconds [51% dmg]
Arm/Booster Destruction (bronze, silver or gold battle-axe with white angel wings, for 1st, 2nd, and 3rd-plus occurrences, respectively) - for destroying the enemy resupply structure within the last 30 seconds [51% dmg]
Node/Egg Destruction (bronze, silver or gold cradle with black skull-and-bones, for 1st, 2nd, and 3rd-plus occurrences, respectively) - for destroying enemy spawn structures within the last 30 seconds [51% dmg]
Stageup Kill (red or blue Roman numeral "II" or "III", depending on player's team affiliation) - for getting the stageup kill for your team to advance to either Stage Two or Three, respectively [51% dmg]
Game ending Kill - last round (white tombstone with "R.I.P." in black) - for getting the last, winning kill in the preceding game on the server, by killing the last surviving member of the opposing team [51% dmg]
Bleeder (black "B") - for doing more than C damage to your own teammates or structures within D minutes [e.g. - C=250, D=2.5]
Feeder (green "F") - for dying to the enemy more than E times without killing F enemies or doing G damage to unfriendlies within H minutes [e.g. - E=5, F=1, G=100, H=2.5]
Teamswitcher (black "Domino" mask) - for switching teams within the last 30 seconds
Hello 
This is not a bad idea, but I don't like this idea of "bonus". It will be more easy for good players to kill (Invisible tyrant, good luck naked rifle !). Just keep this idea of awards. 
Cheers
Yeah, this is about Q3a-style medals, not about any old silly ideas I proposed in the past. Awards, not Rewards. Cheers!