How powerful it is would have a lot to do with what the requisite traits are though. I kind of like the whizkid/badass master trait idea, since whizkid works for pretty much anything now with all the assemblies, and badass seems fairly lackluster compared to ironman generally. Although in this case, I don't think you'd really need to block intuition anymore, since you're not going to see intuition + a mastertrait outside of Ao100 in most cases anyways right?
As far as having int 1 and this... keep in mind that puts you one level away from having int 2 and this, and int 2 is probably the single best trait in the game. Knowing where all your enemies are in addition to know where and how many powerups are on the level COMBINED with increasing the effect of those powers is nothing to sneeze at. Unless you're trying for an ass kicking marine, it makes it really easy to skip by any levels that don't have the right array of powerups and just cash in on the right levels. I think it'd be picked up a lot more than Cateye, which is probably mostly ignored because if you have intuition 2, you don't really need extra vision anyways.
Regarding N!'s bonus (I don't think ITYTD's difficulty matters much anyways does it?), maybe make it stack additively instead of exponentially (So you get 50 turns +(100 + 75)% = 137 turns instead of 100 baseline or 175 if they multiplied (Or the 325 as originally suggested... that'd be way too much.)