what if instead of having the melee phase all melee weapons became a shooting weapon with say a 4 inch range representing a model jumping in to melee then jumping back out. You could keep the advance action and fire any weapon or the rush action and just use the 4 inch melee weapon, alternatively you could make the melee weapon 6 inch and only use it with an advance action. this would be kind of similar to the way that in your original rules, in melee only the charger could hit the model he was charging and the other model wouldn't hit back
This is an old thread, but to be clear for anyone else that might look at it, there isn't a specific melee phase. Once a model (or unit) activates, it has a choice to move+shoot, hold+shoot, rush, or charge.
If charge is selected, the unit must be able to get into base-to-base contact (or as close as possible based on the models used) and then it can use its melee weapons.
I see where you are going with the suggestion of treating all weapons as shooting weapons with varying ranges.