[Satrek2000]

I might add that (at least in my experience) IWDs add weight while EWs don't.

Also, you can bless prepared weapons if you do it yourself, as nobody else is able to wield them. I don't know whether and how applied EWs mess up future blessing.

If you want to change your weapon's configuration or number of slots, the only way to do it is to clean it (/mark it, then use the cancellation-spell). This way, ALL improvements will be lost - there is no refund in diamonds or scrolls already used on the weapon.

As for handlable slots, you can handle 5 from the start, and one additional for each 5 levels of physique. A player of level 19 can handle 8, while one of level 20 can wield 9. These numbers apply to the filled slots, not the number of open ones. If you have a weapon prepared and fill more slots than you can handle, you won't be able to wield it till your physique level is apropriate. You can always fill slots later, to "grow into" a weapon.

A LWW will decrease the weapon's weight by 20%. This may be useful to save weight for reasons of speed, but it's usually a very small effect. As the weaponspeed is not as such determined by the weapon's weight, it will not speed up it's swing.