I like the current system. If you land a Haste, you're sacrificing a 60pt Sacrufice. Plus it adds a little more strategy... if foe is alert enough to see the Haste spell effects, then he can switch tactics and bow kite for 15 seconds.Game would be more boring without it. I know Van rolls solo and wants to maximize sooo viability, even every last little bit, but I think buff others are good for the game. They've already been reduced from 2+ minutes in DFO to 15 seconds.
If you want them to last 5 seconds, they need to be fucking imba.You'd need to make Protection spells give +50 protection for 3-5 seconds to make it worth casting. Otherwise, you'd be better off using a heal, as Nuyur said.If buff-other spells need a nerf, then it's potency of Melee Haste, Ranged Haste, and maybe Ironskin and Magic Shield (the new buff-other from Raw Magic that gives a bit of all magic prots & impact prot)Wards are already pretty underwhelming.