On the subject of 'mandatory buffs', the common features for these abilities are that they either affect the gameplay of everyone in the party (i.e. Trick Attack, Balance), or they affect a subset of the group with 100% uptime (i.e. Slashing Resistance Down, Piercing Resistance Down). I very strongly would like to see a move away from both these types of buffs.

I think the solution is to merge the two concepts. For example, Trick and Slashing could and should very much be replaced with a short duration vulnerability up that specifically affects melee, with an immunity debuff to prevent reapplication. You could do something similar between Balance and Embolden for casters, or between Disembowel and Hypercharge for ranged. This makes the individual effects less game-changing, and also gets rid of those "flavour" 100% uptime buffs that conveniently shoehorn certain raid comps into happening.

There's still the issue of jobs with high burst having a strict dps advantage on low-uptime fights, but it would be a step in the right direction.