Now.. Enimity.. if you don't have a NIN WHM enmity will always be something your raid group has to work around.

So.. AST/SCH both have built in enmity "reduction" AST has it built into their sect and SCH has it from shields + fairie. WHM however is stuck with just Lucid Dreaming. So.. my simple solution is to add an additional diversion effect to Thin Air. Especially as Thin Air is probably the move you're pressing when doing massive healing throuput..

Thin Air:
Reduces MP cost of all spells to 0.
Reduces Enmity Generation by 75%
Lasts 12 seconds.

With these two minor QoL changes I believe personally WHM would have some much appreciated improvements.