At-Wills: Sorry, but this one is terrible. In many combats - especially against Solos, or tough types like Soldiers, there will come a time when the encounter and daily powers are used, and most people are reduced to using at-wills. This change would literally make that part of the battle (which could be 50% or more, if you're unlucky) half as interesting. If you want to increase the At-Will selection, consider letting people take an At-Will from another class of the same role, altered to use their classes stats/implements.
Healing Surges: Clerics have been able to heal people outside of combat in every single version of D&D. Why are people suddenly taking issue with this? Mainly, the issue with this one is it gets rid of 4E's intentional "ready to keep going, at close to full strength" method of eliminating the 15-minute workday. With this rule, it would be quite likely (and logical) for the party to take an extended rest after any non-trivial battle.
Aid Another: Aid Another already works that way - the roll to aid someone does not count as one of the rolls for a skill challenge, and has no negative effects if failed - which it will rarely be, because it's very easy. If you want to make it automatic, go ahead though.
Parcel System: Even if using the system strictly by the book, it never says that monsters would drop gear they weren't using. As you mentioned, parcels that don't fit the monster should be found in a cache or on the corpse of a would-be whatever-slayer.
Push/Pull: This would certainly make push/pull a hell of a lot more effective. Too effective? It depends on the campaign. If you generally fight battles with no terrain hazards, then push/pull don't do as much and could use a boost. If the battles already have pits/lava/fires/spikes/whatever in them, then push/pull can do plenty as is.