Do not take it as an offence, but I think it's a little over the top, at least
for LAWs and RPGs. It could do well with some SAM missiles, though.
Also, take the object (_rocket) itself as a reference instead of taking its
position and then putting it in the drop line.
That is, wrote the DROPs this way:
drop["cl_fire","","Billboard",3,0.5,[0,0,0],[0,0,0],0,1,1,0,[0.5,1,1.5],[[1,1,0,1]],[0],1,3,"","",_rocket]
Also, writing it like this, you could make the smoke behind the rocket and set
the flame velocity so that this one follows the missile (not showed on the
example above)