I just don't see the significance of one more encounter spell per encounter, if bloodied, or two with a feat, if also spending a healing surge.
In fact I would probably want to add more feats to the paragon and epic levels to allow for more recharges, in order to make the Sorcerer "worth it".
Is there a real reason for why you (any of you) think that the recharge is too powerful other than the fact that no other class gets to do it? Is there a broken combo that can be pulled off by sometimes letting Sorcerers use the same spell twice in an encounter?
I mean, sure, the sorcerer will have a little more firepower but that is the essence of the sorcerer. Less options, more firepower. Personally I think the "ban" against memorizing the same spell more than once is so that a wizard can't load up on one spell that would be most beneficial or broken when unloaded multiple times on the battlefield. Also, it prevents making things too predictable, makes it easier for the player to keep track of things and the DM doesn't have to worry about more than one field of Evard's Black Tentacles at the same time (for example).
I'm sorry but letting the sorcerer switch higher level powers for lower level ones seems way too complicated and has no precedence in the rules. Powers recharging when bloodied is a common ability for monsters, especially for dragons, so giving a similar power to sorcerers adds that draconic flavor as well.