Drop the templates. If you go anything other than Cleric 4/Crusader 1/RKV 10/Divine Fullcasting PRC 5 you'll never get 9th level spells, which are made of awesome.
Personally, I like Cleric 4/Crusader 1/Prestige Paladin 1/RKV 10/Church Inquisitor 4 (requires you to be Lawful Good).
Grab Battle Blessing at level 6, this lets you cast all your Paladin spells (which are all of them, since you're a Prestige Paladin) as swift actions, which synergizes amazingly with Divine Impetus. Consider spreading out your RKV levels so that you get higher level maneuvers - your final Initiator Level will be 15, so you could get a single 8th level maneuver if you time it right. You'll also get 9th level spells by level 20, which is fantastic. Final BAB is +18, so you get 4 attacks per round on a full attack, plus a swift action spell (or more, with Divine Impetus), with options for maneuvers if you don't feel like full attacking.
Ruby Knight Vindicator is an amazingly powerful class, and one of my favorites. Have fun playing it, and don't break the game too hard