Re rogue, you mean vanguard rapier, not mord, right? You don't get sneak attack on the mord.
I suspect you actually do more damage with a dagger than a rapier.
Lets see:
damage with rapier: 41 * 13/20 (50% + charge + combat advantage) = 26.65
damage with a dagger (with the Nimble Blade feat instead of the weapon proficieny -- not a constant bonus, so ok with your house rule, right?) : 37 * 15/20 (all that + dagger weapon mastery + Nimble Blade) = 27.5
Mind, I think you're probably better off with rapier for a charging rogue -- but that's because you want to take Flash of the Blade -- which you don't actually have yet. As a charger, you're going to find it hard to get combat advantage--but that's where flash of the blade comes in.
I suspect you actually do more damage with a dagger than a rapier.
Lets see:
damage with rapier: 41 * 13/20 (50% + charge + combat advantage) = 26.65
damage with a dagger (with the Nimble Blade feat instead of the weapon proficieny -- not a constant bonus, so ok with your house rule, right?) : 37 * 15/20 (all that + dagger weapon mastery + Nimble Blade) = 27.5
Mind, I think you're probably better off with rapier for a charging rogue -- but that's because you want to take Flash of the Blade -- which you don't actually have yet. As a charger, you're going to find it hard to get combat advantage--but that's where flash of the blade comes in.