When you say Discipline vs Might/Endurance, do you mean that if your Discipline roll beats their Might/Endurance roll they move 7 zones?
All or nothing, yeah. Only other thing I can think of is adding the shifts to your roll and subtracting the resist roll, which seems more likely to be broken.
The Intimidation item spends 2 shifts to become zone-wide, which is weird for a skill replacement item.
Fair point, I guess. Honestly it feels like the sort of thing magic should be able to do but I wanted to avoid an offensive mental evocation. Actually it feels like the sort of thing Intimidation should be able to do... I'll look into that and see if it makes more sense to rewrite it.
The flashing quartz also spends 2 shifts to hit a zone, which when added to its power of 4 leaves one shift left over.
I think I just used the wrong word level. Its basically just a magical flashbang, anyway.
The reflexive defence items, like most reflexive defence items, are automatically a little bit questionable because the rules never specify which defensive items can be activated reflexively.
YS280, "Defensive items (ones that provide armor or a block, for example) often consume a use at the time of defense and don’t require a separate action to activate." It's up to my GM but they are providing a block. Arguably you could set them up as a trigger on a Mediocre Ward or something like that instead.
I've been keeping him under control by throwing lots of mortals into the fray and compelling him to not use weapon 10 nukes for fear of accidently killing someone. But when we fight "supernatural" creatures, it's kind of a joke, really. He one-shots creatures fairly regularly. Except for the few enemies dodgy enough that he can't hit...which is probably the biggest draw-back of a crafter. It's hard to get your accuracy up there like you can with a straight up wizard.
I see three ways of looking at that. One is your players have basically said that they don't really want the game to be a challenge. Another is that they want to face enemies who are tough enough to take (or avoid) those 10-stress hits without a problem. Or, they're asking for the challenge to come from another direction entirely.
Also, remember zone-wide attacks are NOT selective, so forcing the players into a zone with borders (so they can't move out and act at the same time) and minions means any attack against them is an attack against himself. I also probably wouldn't allow zone-wide blocks, but if I did the same rules and preventative measures apply. They CAN make selective multi-target attacks or blocks, but it requires splitting both the Weapon rating and roll between targets (something I'd definitely adjudicate as needing to be pre-split as part of the item definition).
But mostly I look at it as, how much of your refresh did you use to get up there? 10 point items require some combination of 5 enchanted item slots or 5 focus items. 5 uses requires 2 enchanted item slots or 4 focus item. That's a minimum of 3 refresh if its your ONLY enchanted item. For the same cost you can get Inhuman Strength and Claws for a permanent +4 to Fists as well as some nice side benefits that can't be taken away from them.
But if you tweak it the right way (and your GM lets you get away with it) you can break most mechanics.