First of all, I never said we would, I said it was an option. That being said, we've greatly altered both of these classes (paladin/ranger) to make them much more powerful than they are in base NwN, so toning them down is not out of the question. We will always readjust things, sometimes to buff, sometimes to nerf, and every time we nerf people get upset, so we're used to that, and don't mind it.
As for buff duration, they're not meant to be permanent fixtures; some are, which is why they last hours per level (which in our system means permanent unlike in PnP, since people can rest every 3-4 in-game hours rather than every 12 hours), but others are round/level. It's not a quality of life argument, it's a balance one. If you were meant to be permanently warded, these wards would be part of the class' normal features and be permanent.
There are no plans to extend the duration of buffs, blackguard or otherwise, beyond what we've already done, and we've already extended pretty much all wards by the equivalent of 10 levels already, as most of you seem to forget.