Fire Dragon Exarchs do have other choices besides the fusion gun. Maybe we´ll be lucky? If they make the Dragon´s Breath Flamer available I´m pretty sure I know what class to play.
The melta gun was described as having a hissing sound in the original 40kRT but only as fired. For me the description sounds too specialised/restrictive and isn't in the spirit if the melta/fusion gun, even for eldar. They would in effect be useless against anything other than stationary vehicles. Melta guns were always short range true but I think a recharge is fairer and more playable than sticking them to the spot when they fire, this gun has no recoil, had advanced targetters in the case of the eldar. With a recharge if the player fired early you could have reduced damage output. The way described above I wouldn't want to play a fire dragon, poor range and a recharge is enough.
The weapon is supposed to kill everyone on the line of fire, if you can kill 5 guys with a single shot poor range and a recharge between shots (this is even better than a charge up mechanic) is not enough, we'll see once we get our hands on the game but for now I think that no restriction is enough if the weapon is as powerful as it sounds.
Maybe it's my out of date wh40k knowledge it wasn't an area effect weapon when I played, area based would indeed be a different story balance wise.
It's not supposed to be a huge area, think of a Quake rail gun that goes through people and kill every single one of them in the line, but with a short ranged a fire delay.
