The current difficulty gradient for monsters is completely out of whack.

For example, there are some red mobs that I have no problem killing. There are other red mobs that annihilate me. The game needs to do a better job gauging my capabilities and correctly informing me of a mob's difficulty.

Levequests have their own gradient issues. I can't count how many times I've selected two stars and found the mobs are all red and destroy me. Then changed it to one star to find the mobs are all blue and complete pushovers.

The system should be as follows:
Blue: not worth fighting. No exp from fighting it.
Green: worth fighting. Still easy. Green means "go".
Yellow: a bit above your level. Mildly challenging.
Orange: five levels above you. A very hard fight.
Red: you will die.

But as it stands, I can still kill many red mobs and I seldom ever see green-orange.

Please fix this, SE.