I would make it more realistic and probably less super-heroic.
I would trim the most controversial powers (such as blinding barrage or come get some...).
I would try to remove healing from combats*, making healing power rituals. This would require a lot of adjustment in monsters output damage and HP, of course. It would probably means that combat will be deadlier, so I would decrease the number of encounters required to level up.* Maybe making "quick healing" powers available at higher level (paragon at least)
I would extend the poison/disease rules to critical hit, so that wounds do exist in the world (there is no such thing as a wound in 4e).
I would try to make power sources mechanics more distinctive, somewhat. I understand the precious balance 4e creates with the "everything is a power", but there should be a way to make arcane more different from martial.
I would restrict rituals to spellcasters, probably by power sources, not by skills (multiclassing would allow you to use rituals of said power sources)
I would extend the silo-ing mechanic of powers to skills, so that secondary/utility skills (armorsmithing, sailing, ride...) can be choose to customize your characters without penalizing the most critical skills (detection, arcana, athleticism...)
I would remove the ambiguities between rules and fluff, making them consistent. Example : what are really doing Eladrins when they use feystep ?
I would trim the most controversial powers (such as blinding barrage or come get some...).
I would try to remove healing from combats*, making healing power rituals. This would require a lot of adjustment in monsters output damage and HP, of course. It would probably means that combat will be deadlier, so I would decrease the number of encounters required to level up.* Maybe making "quick healing" powers available at higher level (paragon at least)
I would extend the poison/disease rules to critical hit, so that wounds do exist in the world (there is no such thing as a wound in 4e).
I would try to make power sources mechanics more distinctive, somewhat. I understand the precious balance 4e creates with the "everything is a power", but there should be a way to make arcane more different from martial.
I would restrict rituals to spellcasters, probably by power sources, not by skills (multiclassing would allow you to use rituals of said power sources)
I would extend the silo-ing mechanic of powers to skills, so that secondary/utility skills (armorsmithing, sailing, ride...) can be choose to customize your characters without penalizing the most critical skills (detection, arcana, athleticism...)
I would remove the ambiguities between rules and fluff, making them consistent. Example : what are really doing Eladrins when they use feystep ?