I definitely agree with both your points, mobility tools for caster makes sense being short.
Same goes for DPS, Picto would be fine if other casters were on this level. The problem lies within the role of the job.
I think SMN would be okay at low melee level, as long as PCT and BLM are slightly higher. If we balance too much around difficulty, we would have too much gaps.
SMN could be the castless caster that doesn't have tools to move around, RDM would need one in exchange.
That said, PCT would still deserves an adjust on AoE situations, increase the splash reduction.