Personally, I would drop the Summon Mount ability and Mounted Combat feat. In fact, I'd also get rid of bonus feats altogether.
Not all 'Paladin'-types are necessarily going to be (or even going to be
able to be, perhaps) quite so literally (or quite so
typically, in this precise way) the 'White Knight' figure, Pokemount included. Just my opinion though, obviously.
And feats, well they just don't work for me in this context. YMM, and looks like it probably does, V.
To reasonably accurately emulate (well, replace) a boost in HD (I would have suggested an increase in HD of one die type, *IF* going that way, rather than simply a d10, regardless. . .) - just give 'em a +2 sacred Con bonus; that'll do the trick (+1 HP per HD, from Con, is identical to the average gain from an increase of one die type).
Smite Evil, I would limit to being based on
either Wis bonus
or HD, not both. Wis bonus sounds alright to me, what with MAD out to work its mischief, to some extent [combat stats
and Cha
and Wis?! Oh well, uh. . . at least I don't have to be smart, too!

].
Three levels lower for Turn Undead seems fair, not two. Or is that just my
3e conditioning. . .

Offer a feat in the system used, for raising effective turning level, and hey, no problem anyway, if it's that big a deal.
All that said, LA +1 should be OK. To be honest though, I feel it's a bit weak for any LA. But I'm biased that way (Upper_Krust's appendix v5 to his Immortals Handbook is my current [rough] guide for CRs, ECLs and so on, and when it's not, I tend to think along similar lines anyway). The upshot being, I view
3e's LA adjustments as universally priced too high*, poor value for actual play, however one might wish to phrase it.
* Well, in particular, when it comes to mixing them with spellcasting classes. Big surprise, I guess. Or yeah, really expensive ones that don't compensate for HDs lost, in the case of melee types.