I believe you were saying that if Fire and Stun follow the same rules*, then they are the same thematically. I was pointing to how the theme might treat them differently (although, why one would incur fines and the other wouldn't is a question best left to gonzo-style games). If you don't distinguish between in-game rules and metagame rules, well, there's not a lot to discuss here.
Another example occurred to me, though not from a DRPG...
In a military simulation video game, you can use certain actions to shoot through walls and armor, when under normal circumstances you couldn't. A glitch. Using the glitches wears down the "simulation game" aspect, leaving players with just a "game" to be won or lost, not experienced. Would you avoid glitches to support the simulation, or would you use every tool available to win?
Note that this changes the original question a bit too, because for many, glitching is synonymous with cheating. However, it casts a new light on the rules and mechanisms: the thematic rules say no, you can't shoot through walls unless you're using a strong enough weapon. The marketer's rules (or rulebook) agree: of course it's impossible to walk partially through a wall and shoot your opponent - that's not how the game is designed. However, the code disagrees: if you use the controls just right, shooting through walls is possible with any weapon.
What you're talking about here are exploits. Performing actions that were never intended to be taken, but are technically allowable (assuming you're playing in a game where you aren't subject to a ban for exploiting shoddily crafted mechanics, lol).
And the answer depends on how competitive you are, and how invested you are in playing the way the developer intended. If you're playing Skyrim, and you fall through a floor and find a way into another dungeon, do you explore and poke around, or immediately quit the game and start over? (Assuming you had no way to teleport or otherwise fix the problem- and what if the way to fix the problem is to use console commands? Is that cheating?).
If you're playing an FPS and there's an exploit to shoot through a wall, do you refrain? What if other people do it to you? Do you stop playing until the developer does something about it? Or just "play honorably" and suffer?
This plays into a very interesting topic of socially enforced rules. In MMO's, especially, the player base often "decides" how the game should be played, and will do whatever they can to enforce it, regardless of developer intent, such as harassment of players who deviate from their expectations.
For example, Everquest had this issue where you could attack enemies and get their attention, and they'd chase you to the ends of the game map. Players would gather up large groups of monsters and lead them into supposedly safe places, like towns, to grief other players by having a mob of hostile and deadly foes wander in (this was called "training"). This quickly became a bannable offense. However, due to player demand, a server where NOTHING was a bannable offense was created.
A player then decided to test the boundaries of the "no ban" server by training dangerous mobs of monsters- and immediately the players cried foul, to the point that this player got banned on a "no ban" server- why? Because he deviated from social expectation.
Another example- the MMO's City of Heroes and City of Villains had you playing, as you might guess, superheroes and supervillains. There were a few zones where you could interact, with the intent of battling each other. But over time, the player base decided to use these zones for socializing with "the other side" rather than fighting.
There was a "safe" area of the map where you couldn't be attacked. But one player decided to use his powers to pull villains into the battle and attack them for xp, playing the game as intended. The other players reacted to this violently, even sending the player actual death threats for violating the "social contract".
If, in your games, there is an implied social contract, violating it should receive the same reaction. And such things exist "in universe" as well; you stated that psionics were distrusted by NPC's for various reasons. A player decides to go use a psychic spell because it's "the best". He absolutely should suffer the outrage of the rest of society- his action was legal by the rules, but willfully violated a social contract, possibly in and out of game, since all of this was explained to the player in advance.