I feel like divine seal is a fairly weak effect on a very long timer. It doesnt keep up with the current pace of the game. What I'd like to see happen is have its recast dramatically reduced and then have its effect adjusted to compensate for the change. Something like-

1 minute recast
Cure potency based off the lvl of WHM- (WHMLVL +1)/2

So as a sub job you would get a 25% potency boost and as a 99 WHM it would be +50%. This also would make WHM's more comfortable subbing other things than SCH with them being able to take advantage of divine veil more often.

WHM is really only good at healing, it would be nice to have some of our tools refined.