You can't draw additional text using DrawText on current version of SoldatServer. The upcoming one supports up to three or four separate layers for big texts, so my DrawText would 'cover' these of iMod.
And I don't understand what is wrong... You wanted ID, so it displays ID. Dod you want it to display nick of the player you're attacking? If so, then use this code:
function onplayerdamage(victim, shooter: byte; damage: integer): integer;
begin
drawtext(shooter, idtoname(victim) + ' | HP: ' + inttostr(getplayerstat(victim, 'health') - damage), 330, RGB(255,255,255), 0.12, 100, 240);
result := damage;
end;
You can change the size by modifying the 0.12 part.