So... How many folks have any player characters with more than 2 magic weapons in their campaigns so far?
My character in the Middle Earth PbP game only has one, but he does also have a Holding and a Contact, so I'm spreading the Rep love around a little. I can't see much reason for having more than two magic weapons, unless you have both ranged and melee weapons.
As for the feats, with the Mastery/Supremacy bonuses can you pick an Essence/Charm that your weapon already possesses? If you can, do the effects stack?