The first serious problem I've noticed other than lack of commands such as /assist, is that the target box is always moving.
This is not limited to when a monster performs a lunging attack. even when the monster is in the idle animation it's target box moves, as well as players
this makes scrolling through targets very sparatic.
I have tested this with a party, where multiple player characters are lined up near one another on the screen. The results would have it skip characters completely or toggle back and forth between 2 players due to them changing position in their idle animation.
This not only makes targeting a nightmare, but I sure it also is creating additional performance loads on clients or servers, and possibly both.
On a related topic while moving the hit box for AoE attacks is good for lunge animation, the game seems to actually update the player position as well.
This is a bad mechanic, it requires additional resources and does not guaranty that the player will return to the starting position.
The players position should remain fixed unless changed by player, or by environment (aka knock back, or draw in).
This should help create more consistent game play, less frustration (especially for Marauders), reduce client/server loads and improve tactical play.
While the auto-attack introduction will lessen the occurrence it will still remain an issue with weapon skills.
Targeting in front only, there are major problems with using the action button while on enemy mode, it often selects the player, or players behind the player while a single monster is standing directly in front.
Suggestion is this, ignore all targets that are not in front of player, if there is no target then target player. (target being players or npcs)
This should also be true when using arrows or d-pad to select targets.
This gives more predictable targeting, minimizes number of targets that player must scroll through. It may also improve performance as it takes more targets out of the equation.
Additional text command for macro use, /assist, would greatly relieve current issues that I stated above.
One addition to this list, up/down party targeting for sub-target abilities, healing spells, buffs, accomplice etc. This makes targeting easier for players as other players may not be visible but still in ability range, and limits the target list to a maximum of 8 versus everything on screen.