Weakness to elementals and magic is not an exploit, it's an function in the magic system who has been with us since Daggerfall, yes it's a powerful function but so is power and sneak attacks or fallout 3 location damage.
Now fortify intelligence potions in Morrowind was an exploit, adding a damaging effect to a potion in Oblivion to remove it from the active potion counter faster is a minor exploit.
Now fortify intelligence potions in Morrowind was an exploit, adding a damaging effect to a potion in Oblivion to remove it from the active potion counter faster is a minor exploit.
The Drain Health 100pts for 1s spell was a big exploit though. And putting it in combo with Weakness to Magicka 100% for 1s was double combo exploit bonuses. The exploit here is that those two spell effects were grossly underestimated when put on a 1s duration.
Paralyze at 1s duration was the same, as is a very short Invisibility spell or short Charm for easy mode persuasion replacement. Or a 1s fortify mercantile before talking to a merchant etc...