I am not a high level cleric so I don't know about SP Consumption being an issue...but at least for me if you don't want to spend skill empowerment points then do Cool-down and Basic to +5. SP using doesn't seem to be a problem when you heal an extra +250 when you upgrade heal +5 in basic. Also I just use stones if my party seems to be needing a lot of special attention. But like I said...I am not level 79 so I don't know what it will be like in the 70's.
