Ok there has been many many posts on this and I have not been able to locate this particular idea. If it does exists I do apologize, I did try to search for it!
In the game there currently exists a +/- or 0 after enemies. If we scaled damage and xp to these numbers the problem of difficulty would go away to an extent. EXAMPLE: Any 0 or +/- 1 enemy would give the standard damage and xp. At +2 you would deal 33% less damage to them at +3 it could be 66% and more than that well, you deal no damage. Use the reverse formula for the - but cap it out at 200% damage. I believe that a system is in place but just not this aggressive. It would scale the xp as well to an extent. EXAMPLE: If I slay a +3 enemy maybe I get a 20% additional xp bonus.
It is really simple to personally scale the difficulty of the game now to your liking. To hard? drop down to -2 area/mission. To easy? Jump up to a +2 area/mission. I am sure that something near this is in place now just not this aggressive.
Now lets add in a zone-able death penalty, that every time you die in the zone, you receive a temporary -1, that stacks to this +/- system but with no xp bonus to keep people from abusing this function. It would be removed when you leave the zone.
The final touch to this would be an out of combat + not cloaked self destruct option. (this would be sweet on the bridge option.....) This way a player could purposefully aquire DP to assist lower levels and still have the challenge/fun of the level. This "self destruct" would equalize the zone you are in to your level at 0. It will only scale a player down to zero and have no damage output from the explosion.