Q488: What ways are there to increase your effective Paladin level (even above your total HD/level if at all possible) when determining your Special Mount's abilities or to boost your Special Mount in some other way aside from Prestige Classes that simply advance your Paladin level as if you were still a Paladin and theurgic feats like Devoted Tracker?
I'm not sure this is quite what you wanted, but the PrC Paladin from UA gives you PrC Paladin level +3 stacked onto your mount, so that's a +3 in addition to the normal PrC stacking. There's also the Holy Mount feat that makes your mount levels stack for all divine classes... the combination of which could yield this, for example:
Cleric 6/PrC Paladin 3/Ordained Champion 5/Full casting divine PrC or more Cleric 6
With Holy Mount (and Mounted Combat, a requirement) that would give you 23 levels of Paladin mount progression by level 20, and you'd generally be 3 levels ahead on all your levels past level 8. Plus, 17th level Cleric casting beats the heck out of Paladin casting, and all you lose is a few remove diseases per week and a few smites... but your Ordained Champion and Cleric abilities more than make up for that. Through in Battle Blessing and you can really rock out the swift action casting.
Hope that helps. Sadly, Bloodlines were errataed not to work, so I don't know of any other ways to do it.
JaronK