Feedback:User/Mervil/Item Customization Choices

In Guildwars 1, customizing a weapon gave a 20% increase in damage, no matter what weapon was customized, whether it was an axe, a bow, or a wand. I would like to suggest that a new mechanic be introduced in Guildwars 2 that allows the player to choose one from a variety of benefits given to the player upon customization.

Here are several ideas:
 * damage increase
 * energy increase
 * health increase
 * armor increase
 * attack speed increase
 * casting time decrease
 * skill recharge decrease
 * skill duration increase
 * weapon range increase
 * ranged weapon flight time decrease

These are just preliminary ideas, and obviously some of these could be overpowered. If implemented, each benefit would have to be balanced with all the others, of course. But this would provide a fun and varied alternative to non-melee professions, cause really, how much benefit does a caster get from a 20% increase to weapon damage? A player can have an assortment of weapons in inventory customized in different ways (in addition to different mods) to use in various situations.