Should a Paladin's Holy Weapon be limited to swords only?
I personally don't see why it should be limited to swords only. While I really can't see a Holy Shuriken (just an example), but I can see a Holy Halberd or a Holy Bow.
Powerful magical swords are certainly iconic in historical mythology as well as literature, so I can see why someone might decide that most holy weapons are swords. But there's no particular reason in D&D why holy weapons should be swords only.
I see no reason for swords-only... Maces and hammers come off easily as Holy Weapons. I don't see any other reasons for banning other types except for setting reasons.
I was thinking of creating an Elvish Paladin for the next 3e campaig a friend is planning. I've never run one before, so I was thinking of making a Dex based Paladin instead of a Strength based Paladin, and be really good with a bow instead of melee weapons. My friend encourages us to be creative and does reward creativity, so I was thinking of asking him to let my character have a holy bow.
Swords, Axes, and Hammers I'd all allow with question. Other weapons I would require it to be asked for for thematic reasons and not a min/maxing reason.