The Paladin buffs aren't terrible but nothing to write home about.
Fealty: Grants powerful resistance to enfeebling magic - If this actually made you immune to status effects from mob ws then it could be pretty decent. If it is strictly against when mobs use actual magic on you then not very impressive.
Chivalry: Converts TP>MP - With the recent addition of Ethereal Earring & Auto-Refresh I really haven't been hurting for MP, but it is likely worth at least 1 rank to have access to it, depending on the conversion ratio.
Iron Will: Adds a spell interruption rate down effect to Rampart - I don't think spell interrupt rates are that big a deal for any job, even though this does give AoE spell interrupt down. Might be helpful in a few fights, possibly Bahamut 2, but Rampart's relatively short duration means it wouldn't really last long enough to be very noticeable. Probably not one I would get.
Guardian: Reduces enmity loss while using Sentinel - This one has some potential. Combined with Sentinel Recast delay you could seriously up your hate peak by using Sentinel before a massive line of JA and then just stack enmity even higher. Might be an excellent hate tool.