I think there is a more correct solution to the problem of hardship in the dungeons, as well as a variety of builds.
Need to add collision mobs (of course only for dungeons). Or increase their AI. I remember very well how difficult it was to pass the dungeon until the players do not become abuse tactic: lure mobs in the corner and quickly kill
As for the downed state, I think it is necessary to change the process of removing from a downed state (Rally). I saw that some people raised this issue
I will describe how I see the addressing this issue
Resurrection should only occur after all nearby enemies defeated, and not after killing any mob (or player).
Now the points as it can be done in different modes.
Open world PvE
Rally possible after killing mobs group (1-5 unit or may be more).
Example: A group can be combined wave of mobs at events. During the event, a wave of mobs (20 units) attacks. The player becomes downed state. He can Rallying, if one group (5 unit) completely destroyed (or completely destroyed all wave of 20 unit).
Dungeons
Here can be rallying only after a complete victory in the local fight (for example three waves 20 units), or can use the same as in the Open world PvE
sPvP
Here you can rallying after winning a local fight. Also, reduce the number of «point of downed penalty» required for complete death to 1 or 2.
Example: there is a fight 2vs2: Team A have 1 downed state in the team B 2 downed state.
In the current version of the game, the following occurs: Players team B finishes player from team A, and rallying together and finish off the remaining players A. Winning the local fight to give 2 killings and capture points.
After changing the mechanics rally: Players B Finishes A team player and start killing alive player team A. Player team A finishes at this time one of the players on the team B and himself becomes a B downed state. Further the situation may move in different ways, such as player team B finishes player team A winning local fight rallying and capture points. In the end, Team B gets 2 kills and a point, the team A – 1 kill. Or situation can turn to another, but this result seems to me more correct (or true).
WvW
In the world vs world always, there are times when the two zergs collide and at both sides falls 5-10 people. Following is an attempt to make a Rally. On the part of Zerg A completely kills 1 person and 10 people are in the downed state Zerg B used immediately receive Rally, or worse get rally killed castle guards (for example).
Here rally should remove at all, only in the resurrection by hand or skill.
In Situation 1vs1 or 5vs5 or other variations Rally should work as described in clause sPvP
Offtop:
If the arenaNet be able to do these changes from a technical point of view, and generally make it, then in WvW and sPvP can add another interesting change.
For example giving extra reward players won in an unequal battle (1vs2, or 30vs50).