Overall, i like the direction this Idea goes, but some changes, i think should be approached a bit different.

-Physick: increased Potency and 2,5sec cast time and it has now its own Cooldown with 20-30Seconds (basically doing Emergency Tactics Job as single target Heal)

-Emergency Tactics: turns one single target Heal/Shield into a AoE (Cooldown should be arround the same as Physick, maybe even longer)

-Chain Stratagem should allow something more than just a unsignificant crit buff, maybe something like being a marker for when you Mark Target A with it and Attack Target B with a single attack, Target A gets also hit by the single target effect.

-Bane: I think a better approach on this would be if the effect would explode already existing DoTs on the target for the remaining duration and then apply the unique DoT that follows afterwards.

-Art of War: should get a additional effect, something like bind or knockback for example.