i maxed out my right tree so i will only discuss about the right tree.
shield bash - my only problem with this skill is that you are forced to get at least one level of it to advance in the skill tree. this skill is also completely overshadowed by the attack skills on the left side because stuns are way better than slows (it's not like mobs run away from you). it is also useless to broadsword paladins.
strength of gods - basic heal spell. heals a nice amount of health but has a 3 minute cool down when maxed. the cool down is simply too long. the cool down should be dramatically reduced. to compensate, the heal amount should be lowered a little.
defense mastery - basic passive skill that adds 160 defense at max level. nothing too bad about it. i only wish it added more defense. after all, shouldn't the paladin be the tank class? the divine armor buff adds more armor and you can use the buff on anyone. this passive should be buffed a bit.
provoke - nothing wrong with this skill other than it being useless in pvp
open-ended insult - aoe provoke. good intention, but the paladin doesn't get any aoe skills on the right side. don't tell me they have one on the left side because that aoe skill is the last skill on the left skill tree. this skill is pretty much used only in parties. otherwise, you are just going to get yourself killed.
divine armor - great skill. i feel like they could add a bit of magic resistance to this skill since the right tree doesn't have any magic resist skills.
divine protection - excellent skill for bossing and pvp. however, the duration usually runs out before the actual protection is used up. the duration should be increased and the cool down could be lowered a bit.
divine sigil - this skill is useless. it says it decreases the target's defense by 700 at level 3 but i only see my damage go up by 5 per hit. level 1 and 2 divine sigil do absolutely nothing at all. it also only lasts for roughly 10 seconds. this skill needs to be fixed.
blessed weapons - the best skill in the paladin's whole skill tree. we need more skills like this.
spirit cleansing - nothing wrong with this skill. i don't find a need to put any points in this past 1 because you barely ever get afflicted by more than 1 debuff. the scaling should change from increasing the number of debuffs removed to a lower cool down.
avatar - the paladin's final skill on the right tree. it is nice but it simply lasts too short. duration should be buffed. 15 seconds is enough to kill 1 mob. also, since it increases your max hp and max mp, shouldn't your current hp and mp heal as well? it's kind of pointless to increase your max hp and max mp if your current hp and mp don't increase as well.