So it's mostly knowing which abilities can be placed later and which earlier. Usually, if you have an ability that adds an ability score modifier to defenses or saves, you want it later; you can debate the same on attack and damage rolls, but generally those are better earlier on. Having Divine Grace come up later extends the lifetime of a Paladin since it forces you to remain in the class for a longer time and prevents dipping.
The problem isn't the fact that they should regenerate or not, but that the limitation of uses per day does not fit with the effect. Pathfinder's Paladin's Smite Evil is worthwhile per day since the effect extends well beyond one round; if you wish to keep it as a single attack, it's better to keep it per encounter (that way, you can use smite every attack, but save it for the strongest enemy/ies because you still have limitations on how many times you can use it); that way, you have the ability to recharge them quite reliably.How does regenerating 1 smite every time you get a critical hit in a full round attack?
I dunno...that's pretty strong, actually. Plus, a bit unfitting.Some 5th level spells I considered where,
Dragon shape, Jut polymorph into any dragon that is NG or LG and doesn't exceed your HD.
The Mystic Paladin's spell list should have a few spells that the regular Paladin lacks (Shield of Faith, Aid, Magic Vestment, probably Greater Dispel Magic) and most of the 5th-6th level Cleric spells that aid Paladins (Righteous Might, Mass Cure Light Wounds, Cure Critical Wounds, Disrupting Weapon, probably Spell Resistance; all Mass stat spells, Blade Barrier, etc.) so that they get a solid boost in spells. While looking at Mystic Ranger, figure out which spells the Rangers get that fit their general theme, then get spells for Paladins that work the same. Try adding spells from the Spell Compendium as well (and identify them as such) so that Mystic Paladins get a good variety of spells.
However, things like Alter Self and Polymorph are just too much for a Paladin, even more turning into a Dragon (even if it's a Gold Dragon, which behaves quite a bit like a Paladin).