Fireball is a problem.
It is always a problem. It was a problem in old school DnD when it trivialized combats against multiple opponents, and it is a problem in Heroes By Trade... though for very different reasons. Fireball in HBT is balanced by the numbers but it creates some real problems in terms of feel and theme.
In HBT there are several kinds of magic. One kind is Rituals, which are slow to use and restricted by the damage you take from casting them so they are not generally useful in combat. The other main kind is Powers, which are quick to use, do not require you to take damage, and are primarily suited for combat. The problem I am having right now is that some classes fit into this dichotomy fairly nicely and others do not.
For example, Channelers are martial artists who use their Powers to mash their enemies. They punch and poke and break bones. The fact that their martial arts aren't especially useful outside of combat makes sense because they are built around the idea of mystically disrupting their enemies and that doesn't necessarily work on doors, walls, or other structures. It feels natural.
Wizards, on the other hand, cast Fireball. It envelops a large area in fire and burns enemies, which has obvious applications outside of combat. Pretty clearly you can use this to start fires, destroy property, create light, and maybe even more exotic things like melt some objects. It feels kind of bizarre that performing a relatively simple Ritual costs time and health but blowing up a huge area with fire doesn't. Fireball clearly isn't the only offender here because Meteor, Eruption, and Inferno are just as troubling. I am not entirely certain that this is a critical problem but it is definitely a chunk of the fluff that doesn't quite fit as well as I would like so I have been mulling over ways that I could fix it.
The easiest solution is to simply remove Wizards as a class. Get rid of magical nukers that blast people with fire from range. I don't particularly want to do that though, as the idea of a class that uses magical attacks from range is something I want to include.
The more complicated solution is to alter the Wizard theme in such a way that it doesn't feel out of place. One thing I was considering was changing Wizards to have a musical theme and call them Bards or Songstitchers or something like that. Instead of blasting people with Fireballs they would instead attack with various songs and sounds that deal psychic damage instead of fire / cold / lightning. This feels a lot more in line with the other classes since their Powers would be more obviously useful in combat because they are attacking other people's minds directly instead of blowing everything up. Another thematic option for them is some kind of psionics sort of thing, where Fireball is Mind Blast instead. The last possibility rolling about in my brain is a light themed class, one that burns people in a way that isn't about setting the world on fire, but more about creating beams of light that do not harm friendly targets or furniture but which burn the evil critters. Evil, in this case, is of course from the caster's point of view.
I already have a class that focuses on shadow and corruption so retheming a class to be all about light has some appeal. It might take some work to rebuild all of the fluff surrounding each Power because there are only so many synonyms for light but it would fit into the rest of the world lore fairly seamlessly I think.
See, this is the rough stuff because there are no right answers. When it comes to numbers there are right answers. It is either 3 or 4, Area 2 or Area 5. I can actually figure it out. Fluff though, that stuff is slippery!