Quartz
Hero
Ah... is it +X items that's the sacred cow, or is it the sword +1 specifically? I suspect that it may well be the latter, and that they could actually get rid of everything else. And the weapon +X could be fixed by a simple change: the bonus applies to damage only, not attack rolls (damage bonuses being much easier to balance for).
Even simpler would be to say that the + modifies the critical range, so make it that a normal weapon cannot crit, a masterwork weapon crits on a 20, and a +5 weapon crits on a 14-20.
But even that can work to the game's advantage - power phrased as "once per round you can..." are more interesting (but generally less powerful) than a static +X bonus to something.
That adds complexity, though. The static effect and at will effect - be they a bonus or whatever - are far easier to administer.