Yeah definitely don't need to dispel poisons. The biggest issue I had pre 40 were paralyze fights, specifically the Chimera boss in Cutter's Cry I think it was? Throws a lightning ball at you that follows you, maybe it disapears after a while I haven't tested it enough but it basically 30sec paralyze you and that's extremely annoying since it makes you fail your heals repeatedly. But Brayflox was easy, even though the fight lasted forever cause the tank tanked the dragon in poison for about 5mins before he figured to move it, and I still had no issue keeping him up the entire time as well as healing the rest of the group.