So, a lot of classes have some mechanics that they don't get until later into the game, adding on another mechanic to their class that sorta makes the job either feel incomplete beforehand or makes playing the class a little wonky afterward because now you have to fit these new mechanics in.

For example, Bard. Bard's get Wanderer's Minuet at level 52, which isn't a huge distance from level 50, but, because of the 52-60 job actions being locked behind entry into Heavensward, you're stuck with only 2 songs for all of ARR. This makes learning Bard's rotation a little wonky, so I think the easiest solution would be to swap when you learn Wanderer's Minuet for when you learn Battle Voice. Now, you have all of your songs, and thus your core rotation, at level 50, during ARR, so you can get used to that feel. Then, once you reach Heavensward, your first action gained is a raidwide buff that you can begin learning how to use as content scales up and other jobs begin to get more raidwide buffs.

Another example, also with Bard, is Apex Arrow. This is an action that you get way off at level 80, and while not a huge change to gameplay, does require you to now suddenly have some awareness of an action that you previously didn't for the last 79 levels. Given the changes Bard has undergone, seeing less emphasis on the DoTs, I think that Sidewinder would be better served as a precursor to Apex Arrow, rather than an ability on a 60s cooldown. Simply make it function the same as Apex Arrow, but with a lower potency, and then it upgrades to Apex Arrow at 80.

Another example I had in mind was with Dark Knight. Bloodspiller and Quietus are actions you don't get until level 62 and 64, respectively. And given the parallels the class shares with Warrior in it's usage of these actions, I feel it might be a good idea for Dark Knight to also have low level versions of these actions, like how Warrior has Inner Beast and Steel Cyclone. We could bring back Scourge for the single-target precursor to Bloodspiller, though Quietus's precursor would likely require a new animation and skill name entirely. Now Dark Knight has access to its Black Blood gauge in the 30s, rather than in the 60s.

These were just some ideas that I had while thinking at work from time to time. I don't necessarily know how well-balanced these sorts of actions at such low levels would feel, but I just wanted to voice and share them with the community.