This is just absolutely nonsensical. No, AST's opener and 2m burst windows being spastic does not show that more DPS buttons would strain healers. There was not a single fight in all of Asphodelos (Savage) that required the full use of a healer's toolkit to the extent where more DPS buttons wouldn't work, not even Scholar. We can simply look back to Stormblood to see what a healer with more DPS buttons would perform like. Scholar had Broil, Bio II, Energy Drain, Miasma, Miasma II, Bane, Shadow Flare and Ruin II (4 more DPS buttons than it has now) and Scholar was completely able to heal all of Omega fine. The first two Ultimates came out in Stormblood as well, and again, Scholar was able to perform totally fine and was even meta throughout Stormblood. AST's opener is awful because it's oGCD heavy, it has nothing to do with "what more DPS abilities would look like", there's no basis in reality for you believing that.
Further, if you think Scholar's design elements are bad, just play Sage? For you, Sage is "snappy and responsive", but for me, Sage is absolutely the most boring job in the game, especially when juxtaposed with Scholar. I don't want to change Sage to fit me even though I think it's an incredibly sterile job, so there's no need to change Scholar even more than it's already been changed to fit you if you already like Sage, especially when the things you don't like about Scholar happen to be what a lot of Scholar players enjoy about the job.