I think some posters in this thread are right when they say there are good reason to use different tiers of the spells, especially in regard to hate and mp regulation.

However, I also feel that the clutter in XIV is an absolute issue.

Why not make it so that when you click on Fire, for example, that it gives a radial menu where you can choose the different tiers of the spell?

I also feel this could be used to reintroduce options to change between single and multi target, which also has tactical benefit for casters.

Each option could change the casting cost appropriately.