Honestly surprised nobody suggested dragoon.
For melee:
Samurai isn't that fast of melee but it's not slow, it's not too hard to pick up. However they do have the most gcds to press because the kenki gauge.
So you would be doing shinten a lot so I wouldn't recommend samurai.

My suggestion would be dragoon for melee. Reason being it's the slowest out the 4 melee.
It still has a lot of ogcd but you don't spam them like samurai.

Though honestly, the melees press a lot of things so honest opinion is to not play them.

I wouldn't bother with any physical range sadly.

Brd is the worst to play with your condition, same with mch and dnc as dnc is proc base and mch is very fast pace with tons of ogcd to press repeatedly.


For magical:
I would say rdm for ease of use and not too spammy.
BLM is iffy because it is pretty spammy and can be fast.

Tanks:
Honestly...any of them.
Though pld,war and dark are a bit spammy on their burst but its nothing too fast pace you have mash and Gnb is the fastest tank but not very spammy.
Though gnb I would probably test out last because it is the dps like out the tanks.