Casters in FL?

[Esmoire]

Skilled casters are often the #1 damage dealer in FL right now, though good DRGs and BRDs are decent competition. What makes casters special is we have spammable ranged AOE, where as other roles often requires proximity and risk for their AOE. This is the main feature of our entire role when it comes FL, and our primary contribution to a fight. Compared to melee our ability to score actual kills is a mixed bag with our best gimmick usually coming in the form of Phantom Dart burst sequences, but what we are doing is dealing thousands and thousands of damage with every GCD if we target clusters of players. Raw damage count alone is not inherently impressive, but what happens is we exhaust enemy resources: potions, CDs, heals, etc., forcing a retreat or outright getting people killed.

As a caster in FL, your main focus should be getting as much AOE damage out as possible, switching to ST for targeted pressure or to secure kills. Your main target: enemy ranged and healers, who often cluster in the backline, pressuring them to get them out of the fight. As you said, our chase is our biggest weakness. Ranged physical and melee have superior mobility, so let them handle pursuit of targets. As an aside: a single Red Mage can lock down up to four enemy players in rapid succession so it's not that chase is nonexistent, though you have to be reeeeaally careful with this since it's very easy to die without the 30% DR melee and tanks get.

Anyway, while all three casters have some great CC that can help lock things down, you kind of accept that we are much more finicky about who we can target versus our physical counterparts. You are going to carefully balance positioning and change targets often to secure as much damage as you can with every cast. Don't fuss too much over people getting out of range and just readjust.

Edit - Since you specified at the start: I play mostly SMN but I will play RDM if our alliance needs more lockdown and healing. For my credentials: I consistently perform highly for my alliance on Primal, so I'd like to think I know a thing or two about the role. I am not perfect but I think I am experienced enough with these two jobs in FL to speak for them. While I don't play BLM a lot of my best competition does and I have a good idea of what they are capable of. All three are amazing in their own ways.