SAM and RDM are consistent and easy. Not much you can do to screw up unless you try really hard playing bad. They've played pretty much the same since release with very little variations.

MCH, DRG and SMN are constantly changing every expansion and patch. NIN and BRD are genuinely hard, so might wanna avoid those too.

MNK is getting reworked so we don't know.

DNC no idea. Heard it's a "just press whatever lights up" sort of proc rotation, not too hard and apparently engaging.