BLM dps is great as is. If a BLM is having trouble with a fight then that's on them. Even in random comps that don't cater to a BLM's strengths (i.e. running a MNK/SAM/DRG as the other 3 dps) BLM can pull some hefty weight on their own. Knowing the fight is more key for a BLM than arguably any other dps class due to how critical it is to minimize movement.

As for casters in general, or really any kind of "off-role" ability, I like that stuff. Making everything fit within too tight of a role confine reduces it's interest and value as a unique job. If RDM and SMN lost raise, or BRD lost it's Esuna, or DNC lost Curing Waltz, then you kill a little bit more of what makes each job different. As a DNC I like knowing that I can top off the raid after a stack aoe, and the healers I've been running with have come to appreciate that as well.