Macro IF into all 4 heals, not worth saving it imo and gives me 1 less thing to think about
I do the same. Free heals with higher crit chance are always good. Other mana cooldowns take a bit more planning, so I don't recommend macroing them.
Try to go into each attempt with a plan regarding your mana cooldowns, and try to make use of your longer cooldowns early in the fight so they will be available again in the later stages of the fight. For example, on Majordomo I spend my mana aggressively during the first Scorpion phase, then pop a Shadowfiend and Hymn of Hope after the first jump during Cat phase. Make sure to PW:S for Borrowed Time before popping Hymn.
Also if you raid with Shamans, get them to call out when they pop Mana Tide so you can make sure you're in range.