I'm really late to this this discussion, and only a read a few pages so this might have already been mentioned but... here goes nothing.
I think it is okay for conjurer to keep the elemental nukes it has. Conjurer is not white mage, conjurer is a user of the nature based elements. That being said I highly anticipate they will add a second job to conjurer down the lane called Sage or something that is a master of the nature based nukes. They will probably get Flood, Quake and Tornado. As well as some other interesting nature based spells. I don't see anything wrong with this imo. Having just one magic DD that does everything is boring. Its more fun when you have a variety of different jobs useful in different situations. For instance if you were fighting titan (water still beats earth right? such a weird elemental wheel.....) you might want to take a sage as your DPS instead of a blm, and I see nothing wrong with that. With the class/job system FFXIV encourages the leveling of multiple jobs, you could just limit yourself to one, but why not level both nukers and switch to the one that is better for the occasion. I think it will add variety and longevity to the game. Also, no one knows how blm has been changed yet. I honestly hope they fixed the blizzard elements and added Blizzaga. We'll have to wait to Beta Phase 2 to see that I believe.
Edit: Also while I'm here, the whole archer bard thing. I think they will probably job add a ranger job quest line to archer with new ranger abilities. Some people well say then brd and ranger won't be that different because they have the same class skillset. But I counter with we have no idea how many abilities jobs are getting or how the job system changed so I think it will work.
Also, bards do have instruments for those who were saying otherwise. Their bows turn into harps, hopefully we'll see more of this. Actually hopefully these harpbows become brd's main choice of bow with special song effects with Artemis Bow being the best until endgame weapons come out. I remember SE saying that when bards sing songs their bows will turn into harp form for 2.0, should be interesting to watch.