Are aren't very experienced with MMORPGs, are you?
(Not meant in a bad way, it just shows. What you're describing is not how this works, and in fact it isn't even MMORPG specific. Even in other games you align burst; say in a MOBA someone CCs and then everyone dumps their burst skills onto the CCed target. You don't just press them ~whenever.)
The goal you're after "I want to make combat rotations less staticky" is good. And in fact IMO it's the biggest thing the devs would need to go after to make combat less samey and boring in FFXIV. But the idea you have "Make buffs not align" would not cause this, in fact it wouldn't move the needle. It'd still be a fully static combat flow for every job, just a different one than the one you do now. This is because neither the encounter nor the job have (with marginal differences on Dancer but not enough to make a difference) no variable/random elements, and hence naturally will have a static, pre-determined, optimal solution for every single encounter. "Encounter" here also includes the teammates around them and their solutions, meaning the group as a whole can find an optimal solution, this will naturally include alignment of big bursts to buff windows, whether personal or shared.
