If we are at it, I would also trash Flare Grenade (we already have Incendiary Grenade and Flare) and Tachyon Grenade (tachyon does not explode and hard to fit tachyon accelerator into little grenade --- mine is a different matter, as is a missile with tachyon-beaming warhead).
About Flare Grenade I'm not sure. If the Flare is chemical or electrical and can be picked up and used again as in XCom, surely it shouldn't be called Flare Grenade. If it explodes --- how does it differ from the Incendiary Grenade? Or perhaps it is a standard magnesium flare, as Centron proposes, that is fired into the air and floats down slowly on a parachute, burned down before it touches the ground? Which option do we like best?
BTW, one important question: is there planned an Incendiary damage type, different to Fire damage type? If not, I suppose the fact that the fire should last several turns, light surroundings and, perhaps, spread, will be handled by a separate weapon flag? But how will we tell that this particular fire particle comes from an Incendiary weapon, while another is just from the old Flamthrower? Unless the Flamthrower fire is also going to last several turns and so all Fire damage becomes Incendiary damage without name-change...