Smaller enemies are hard for everyone. The small critters have some pathing issues that haven't been corrected yet, but you don't encounter them besides spiders after Caverns of the Wild so it isn't that big of a deal right now.
Everyone has directional attacks. So if you move sideways and swing your weapon you'll hit everything in front of you. Forward does an overhead attack, and backwards does an uppercut attack, all with varying damage modifications. It wouldn't be a problem if 2h maces had a knockback effect, but they would need to add in something similar for most other weapons. The slower attack speed of a 2h is offset by the increased damage and secondary stats already.
Melee classes can chain their basic attack nonstop, so that is why the ranged classes can do the same. Adding in a draw back effect is essentially the same thing as reducing the attack speed of the ranged weapon for a max damage hit, but then adding in several variances based on how far back it was drawn. That kind of system makes sense in a game like Skyrim where fights are small and controlled, but probably not so much when the main objective is killing a few hundred enemies during the course of a dungeon run. This kind of system already sort of exists now with the difference between 1h crossbows, 2h crossbows, and bows. They all have different attack speeds with different damage ranges.
I agree that ranged classes should have some kind of directional attack similar to what melee has, it would just need to be balanced. An aoe attack in melee range also means you're taking damage from everything around you, while an aoe attack from ranged is a lot more useful for maintaining distance. As for different elements, they've already stated that they have a full suite of Frost based skills for the Wizard.
Also remember that eventually enemies will be able to do everything a player can do. So directional attacks, charging attacks, all of that kind of stuff sounds good until enemies are constantly ramming into you. Cacodemons were some of the most despised enemies in the game before they were largely removed because of their knockback ability sending players to their death in the Lava dungeon.
Blocking in the game is an active ability you need to execute, and while you're blocking you can't also attack. It makes blocking very powerful in the right kind of circumstances. Adding in stances that offer some kind of passive blocking ability means the entire block mechanic would need to be reworked, especially for classes that don't typically use shields.