I'm not sure of the new "formula" for LoH. However, I can give a bit of insight for all the new-ish paladins:
#1) LoH is no long a regular ability as they have moved it's location to the "class" tab of our AA window and has a total of 17 tiers. (though you still get this AA at level 1 when you begin your paladin) You will get the first 11 "free" as you level to 80 or 85 (cannot remember which) and then they begin to cost you AAs, believe it starts at 4 AA per rank.
#2) Doesn't seem to be 32 x (lvl) + 1 as my level 85 Paladin (LoH (he is at 11 / 17 on the tiers) or healing AAs, and no worn healing focus) heals himself for 29,751 (non-crit)
#3) Doesn't seem to be effected by worn healing focus effects, I have equipped my 60% increase to healing item, and still heal for 29,751 (non-crit)
#4) LoH can be hastened down to a 24 minute recast with all 4 ranks of Fervent Blessing (reduces by 12 minutes per rank) 72 - 48 = 24
any questions or comments you may send in-game mail to Erollisi.Jessie