Just for clarification (cos I suck): Sacrifice doesn't take a long time to cast (although certainly long compared to heals from an EE or bishop), it takes a long time to get where you can use it effectively.
Ok for your heals
Divine Heal is a self heal you learn up to level 40, both DA and Palis get this, its a really slow cast time takes about 104mp and heals for about 250
Holy Blessing is the same cast time, really long, can target other players as well as yourself and heals in the 450 range at 200 cost in MP.
Sacrafice is your main healing spell, it takes your HP and gives it to another player usually at 15% loss to the spell power. What i mean by this is, if it costs 1000hp to cast it, your target will get about 850hp healed. The cast time with BSPS is about 1.5seconds at most, if you have Acument its really fast, and, at mid 60's I can pump more HP into a target per heal then our EE, and I can Rival Bishops.
In PVP its amazing because no one expects the big armored guy with a shield to heal the squishies, I have been very successful with that, plus giving away your HP when you have Full CP is not that big of a deal.
The 30% life thing is Angelic Icon. This basically will boost your stats by 10, 20, or 30% based on its level. Stats effected are Attack speed, Run Speed, Crit Rate, Pdef and MDef. This skill can make all the difference in a 1x1 battle, I have not had much success in mass PVP with it, need mroe testing. PVE it is just plain Godly. With VR, i can kill half the forest of the dead in one minutes time. Ok im exagerating a little, but, with VR and AI I can go from 6 mobs killing me at 700 hp, to many dead bodies around me and nearly back to 3k hp.
We also get the only AoE root spell for a tank. Its nice in mass pvp when it lands, and works well PvE when it lands (its not the most reliable heh)
Between a DA and a Pali, PvE, there is no difference imo. Soloing if you solo the right spots(undead areas) you can level just as fast as a DA with his cat out even though he will kill a bit faster. For tanking you have the same stuns, pdef and such. DA's get life scavenge to keep HP up, you get self heals. The only difference is for big AOE tanking, the paladin has an edge with their 360 degree shield toggle.
Come PvP time, both are a good class now. You can heal your allies, root your enemies, stun alot, and if it gets to pinch Angelic Icon can help you dishout some damage. The DA though has his panther, which 1x1 he will be the better choice near every time. In mass assuming his panther is not destroyed by an erease spell, he will dish out far more damage than you, however your job is to be more of a guardian in PvP, drawing agro, rooting mass amounts of enemies, healing your allies, stuning when necessary and able, and then in a last ditch effort throw holy icon down before the end, for a glorious death ;).
At your level 76+ skills, touch of life is amazing, and IMO greater than touch of death, but thats just me and my play style. There is also a very very end game build out there for paladins, that with the right gear you can use sacrafice on your self to gain HP, in decent qunatities. 400-600 ish if i recall. So that means heres free HP at no cost to you -1400hp to gain 2000hp, I cant wait to try it!