Sorry I just came back from the oooold days several months ago and like a lot of people I was a bit disappointed in Paladin. I've been toying around with some ideas ever since. I'm sorry if my info is wrong in some parts but I'll give it a try ^^
(this is sort of a mix of several ideas in the thread)
Damage taken should have some bearing on enmity loss. When you "hate" something and give it a good slap, you should get a feeling of satisfaction, and that would make you less angry at the target. (sorry for the real world example, but it's such a basic idea I have no idea why it's not in the game)
This would lead into my second idea, which isn't really mine since I believe a magic defense stance has already been mentioned, probably more than once but I only got to page 50000 of this thread before I just decided to post. There could be a magical defense(anything non-physical) action, similar to rampart (I don't really care about the "massive enmity", and also make it sword specific) though. It could last semi-long, and have a reasonable recast, although the key would be to make it either cast on the PLD only or just make it much more potent on him/her than other pt members.
In conjunction with the primals being basically magic, the less hate lost when hit.
Then a situation like this could arise:
-AoE magic attack with magic barrier skill up
-another player (let's say WAR ^^) takes more than twice the damage you do.
-you cast holy succor on the WAR and restore the HP of both, the WAR loses some hate while you gain a ton.
that should satisfy the people with enm problems anyway too.
lastly, swing sword faster, with a bit faster TP build. Reduce shield bash to 15 sec recast to satisfy the people who like fighting with shield. this should keep a nice base hate rate while you use other actions and slightly raise dmg output(I'm not sure how hate works on shield bash anymore, I'd suggest less enmity per bash in this situation).
This would make PLD a nice finesse class you could be proud of, and open to different builds/play styles, while not impacting WAR fans, since a WAR could still make a fantastic speed tank while being able to tank physical mobs, albeit with a little more effort (I love WAR btw so don't think I'm a hater, just don't want it to be the only option).
TL;DR: Don't bother, I'm sure a lot is wrong and too intricate to implement
Sorry for writing this 1000 page novel on the boards.