Odin, good work there.
I've applied some small modifications to make the effects MP compatible as follows:
From findIED.sqf, extract all the code related to effects and move it to an independent script:
// rovingIEDeffects.sqf
private["_i", "_posx", "_posy", "_posz"];
_posx = _this select 0;
_posy = _this select 1;
_posz = _this select 2;
for [{_i = 0},{_i < 5},{_i = _i + 1}] do
{
drop [["\Ca\Data\ParticleEffects\Pstone\Pstone.p3d", 8, 3, 1], "", "SpaceObject", 1, 10,[_posx,_posy,_posz -10],[0,0,-2],1,10,1,0.2,[2,2],[[1,1,1,1],[1,1,1,1],[1,1,1,1]],[0,1],1,0,"","",""];
drop ["\ca\data\cl_basic","","Billboard",120,5,[_posx,_posy,_posz - 10],[1.8,2.8,0],1,2,1.55,1,[2.5,6],[[0.35,0.3,0.25,0.5],[0.35,0.35,0.25,0.4],[0.35,0.3,0.25,0.2],[0.4,0.35,0.3,0]],[0],0.2,0.2,"","",""];
drop ["\ca\data\cl_basic","","Billboard",120,5,[_posx,_posy,_posz - 10],[1.5,2.5,0],1,2,1.55,1,[1.5,5.7],[[0.35,0.3,0.25,0.5],[0.35,0.35,0.25,0.4],[0.35,0.3,0.25,0.2],[0.4,0.35,0.3,0]],[0],0.2,0.2,"","",""];
drop ["\ca\data\cl_basic","","Billboard",120,5,[_posx,_posy,_posz - 10],[1.2,2.5,0],1,2,1.55,1,[1.5,5.4],[[0.35,0.3,0.25,0.5],[0.35,0.35,0.25,0.4],[0.35,0.3,0.25,0.2],[0.4,0.35,0.3,0]],[0],0.2,0.2,"","",""];
drop [["\Ca\Data\ParticleEffects\Pstone\Pstone.p3d", 8, 3, 1], "", "SpaceObject", 1, 10,[_posx,_posy,_posz - 10],[0, 0, -2],1,10,1,0.2,[2,2],[[1,1,1,1],[1,1,1,1],[1,1,1,1]],[0,1],1,0,"","",""];
drop ["\Ca\Data\kouleSvetlo.p3d","","Billboard",1,1.0,[_posx,_posy,_posz - 10],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop [["\Ca\Data\ParticleEffects\FireAndSmokeAnim\SmokeAnim.p3d",8,5,0],"","Billboard",1,10.0,[_posx,_posy,_posz -30],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop ["\Ca\Data\kouleSvetlo.p3d","","Billboard",1,5.0,[_posx,_posy,_posz - 20],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop [["\Ca\Data\ParticleEffects\FireAndSmokeAnim\SmokeAnim.p3d", 8, 20, 6], "", "Billboard",1,200.0,[_posx,_posy,_posz - 10],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop ["\Ca\Data\cl_fireD","","Billboard",1,3.0,[_posx,_posy,_posz - 10],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop [["\Ca\Data\ParticleEffects\FireAndSmokeAnim\FireAnim.p3d", 8, 1, 8], "", "Billboard",1,1.0,[_posx,_posy,_posz -50],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop ["\Ca\Data\cl_fireD","","Billboard",1,1.0,[_posx,_posy,_posz - 10],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
sleep 0.001;
drop [["\Ca\Data\ParticleEffects\FireAndSmokeAnim\SmokeAnim.p3d",8,5,0],"","Billboard",1,40.0,[_posx,_posy,_posz -50],[0,0,0],1,1.3,1.0,0.0,[100],[[1.0,0.7,0.4,1.0],[1.0,0.6,0.4,0.001]],[0],0.0,0.0,"","",""];
};
Now, in findIED.sqf, at the position where effects code was removed add the following:
// effects for IED ====>
[_posx, _posy, _posz] spawn
{
private["_posx", "_posy", "_posz", "_trigger"];
_posx = _this select 0;
_posy = _this select 1;
_posz = _this select 2;
_trigger = createTrigger ["EmptyDetector", [0, 0, 0]];
_trigger setTriggerActivation ["NONE", "PRESENT", false];
_trigger setTriggerArea [0, 0, 0, false];
_trigger setTriggerType "NONE";
_trigger setTriggerTimeout [0, 0, 0, false ];
_trigger setTriggerStatements ["true", format ["res = [%1,%2,%3]execVM""rovingIEDeffects.sqf""", _posx, _posy, _posz], ""];
Sleep 6;
deleteVehicle _trigger;
};
Still have some doubts about your scoring system, if Killed event is not broadcasted then it should work fine, else you might be adding score even to the enemy players.