You're going to get answers for each job here. As you almost already have. My suggestions are Dancer or Red Mage.

DNC is actually something I'm new to. Unlike Red Mage, I don't have another character for it. So, feel free to disregard my suggestion on it. But! It's rotation is literally an RNG proc chain. You press your first 1-2 combo. Did something light up? Press them. Did something else light up? Press it (which one you press depends on if you're Single Target or AoE). Again, did something else light up? Press it. It's the same for AoE. That's the "meat and potatoes" to DNC DPS. You also have two Step attacks. Standard step is you press the button to start it. A button will light up. Press it! Another one will light up. Press it! Then, your Standard Step will light up and you press it again to activate. Techenical Step at level 70 is the same thing except with 4 button presses.

If you can press buttons that light up, then you're already mostly there with DNC. Another nice feature is you never have to stop moving and have a Dash with 1/2/3 charges depending on level. Mechanics are much easier with all the movement afforded to you.

Red Mage has a gauge that you have to balance close to each other between White and Black magic. Because of this, it's relatively difficult to not know what to press next. It perfect conditions, it has a flow to it that is easy to get used to. It goes even further with this idea because of Dualcast. Dualcast makes it so whenever you hardcast a spell, the next one will be instant. Your spells will be broken up into "short cast" spells such and "long cast" spells. Use your short casts to prime your longer ones. Then, you just throw in your oGCD abilities and you've pretty much have RDM figured out. It has a bit more technique to it to min/max with proper timing of your buffs and oCGDs that move you. But, it's still relatively easy to get used to.

Out of DNC and RDM, I personally think DNC is a bit easier. I've been really enjoying it lately. Could just be because it's new and because I have a friend I play with that I enjoy buffing. Another reason I'd suggest DNC over RDM is at lower levels, RDM can be a little bit wonky whenever you don't have your full melee combo or certain buffs. DNC has a majority of its basic DPS tools early on.