No need to sing the swan song of AoK design again. If I understand the functions of GenieEd correctly, things such as altered stats or different missiles only work if people also download and use a changed dat file.
Not many people will go through the hassle and have their dat file replaced for every scenario they download. Also, they would need to change the dat file anytime they choose to play a different scenario/campaign. If they just played scenario X with the patched dat file X, they would need to change that dat file to patched dat file Y again if they play scenario Y. And then, if they have played scenario Y, and somehow feel they want to try scenario X again, they'd also have to change their dat file for that scenario again...
Even if you have the nerve to do that (I don't), it is easy to get confused - because one patched dat file just looks like the other. So "abusing" GenieEd for mamelukes which fire 50 range firebolts may be possible, but the effort to install such scenarios is probably just too big, and too restrictive for players to really consider it.
Take away that, and the remaining functions of GenieEd are quite useful: You can create and detect hidden units with triggers now, which gives designers some nice extra possibilities. If I got Berserker right in his other post, those triggers will also work if other people play it on their computers, without changing their dat file.
Ingo