The Diablo Formula and how Diablo 3 falls short

[FireIceTalon]

There is almost no error in some of these. Crap like vortex, arcane, desecrator will crap on you regardless of how good you are, and they spam their cc effects. Well, some would say spam invincibility/or stay away if you are ranged. But that's the problem. You can't expect perfect play in an imperfect environment. Latency's an inevitable part of the game, and well... shit happens.

Also, traps seem to do ridiclous amounts of damage disproportional to the damage of the act they're in, especially fire grates. There is no reason why I should get 2 shotted by these things if I have good gear.

That's because those attacks are currently bugged, or your resistances are.
There is a part of the damage mitigation chain that isn't (fully) working anymore since the hotfix on 29th June, and many of these damage sources do significantly more damage than they did prior to this.

There was a person on the official forums who happened to keep track of how much damage he was taking from the flying creatures in A3 that spit fire (to compare the effectiveness of some equipment), and he mentioned that they sometimes did up to six times as much damage since the hotfix, while strangely, sometimes they did "normal" damage (in line with pre-hotfix) as well.
There are other issues with elites using their abilities more often as well, with somewhat humorous screenshots depicting an Arcane Enchanted elite pack that has over 20 sentries up at the same time that keep popping up from different people.

It's been 2 weeks now, and not even a response from a Blizz rep about any of these current issues even with the exposure they get on their forums, so seems like we have to wait for 1.04, as the upcoming 1.03b patch seems kind of thin.

Demonic Hell Flyers definitely have bugged damage. My Wiz with 750+ fire resists and near 45k hp was almost dead just from 2 fireballs from these things. When I was doing the signal fires quest it was a complete nightmare to deal with them, compared to the Fallens and the Demon Troopers.