It's funny to see so many people saying FoF has a high risk, my personal strategy for almost the entire game has been to just flame the tank. 1) walk Eder into a clump of enemies, 2) walk my main and Aloth slightly behind and flame everything, 3) repeat flame, 4) collect loot. It really takes off at level 5 once you can grab vigorous defense. Silly mages couldn't actually hit Eder if they tried. And they have, hundreds of times. Guy doesn't even get grazed without a reflex debuff. Of course, the mages on the other hand will instagib each other if the positioning gets too sloppy. This is on PotD with a non-bugged Eder. It's a bit silly, honestly.
I can't comment on mage balance vs druid or cipher as I haven't mained them yet, but in the context of other mage spells I would argue that FoF could use a slight alteration. I like that it's so powerful, damage wise (devs have done a great job keeping at least some spells from each level relevant throughout the game), but it outclasses so many other damage options and all the other level 1 spells that something needs to change. Possible changes from best to worst:
Better encounter and monster design - why is burn damage basically the best damage type throughout the whole game? Why are 90+% of encounters pure tank and spank (for which FoF's positioning disadvantages are irrelevant)?
Buff the competing level 1 spells. Most of the single target alternatives do less damage and do not have strong enough debuffing effects to compensate. They're also riskier to use: any aoe on a group of enemies is almost guaranteed to be of some use because of multiple hit rolls, but single target spells are often completely wasted by a miss, particularly at low levels when wasting a spell is particularly detrimental. I think this risk is actually a bigger problem than either the low damage or effect. Increased accuracy on these spells might help. Better effects might help too (priests can inflict stuck at level 1 with halt, which is ridiculously powerful - halt doesn't do damage, but also isn't a touch attack). Slicken probably needs to be completely reworked at this point, the old version was lol, the new version is terrible (not sure why so many are still supporting it - am I missing something?).
Buff the competing nuke spells. As others have mentioned, the missile spells are essentially all completely outclassed by everything else. Like much of the itemization problems they seem to have suffered from the DR changes before release. They need better damage, possibly in the form of increased DR reduction, increased accuracy, or even auto-hit. Fireball could use an aoe buff considering it usually hits the same number of enemies as FoF but does far less damage (1 to 1, fireball does have its uses but its more of a niche spell than FoF).
Nerf FoF. Last resort. I wouldn't want to see the damage reduced, but honestly one idea that might actually make for more interesting strategy would be to block damage behind targets. It would actually make sense and could even be tactically interesting, eg when a ghost teleports into your group you could flame into it without hitting the squishy caster directly behind it. However that would require there to actually be more tactically interesting encounters in the game, of which there are few, otherwise it would be too hard a nerf.