You don't calculate healer weights in the same way you calculate DPS weights, because as opposed to DPS roles, healers don't maximize throughput with every GCD resulting in some kind of a measureable action. You never maximize HPS and heal on cooldown, thus counting weights for your healing game becomes hard. You can calculate the statistical increases for heals with both CRT and DET, but not for SPSP (unless you literally heal on cooldown). However, due to CRT synergy with Adloquium, it is pretty much a given CRT stacking is the norm (and how enmity issues never arise on a SCH with crit-shields being nice regardless of the heal).

If you want to calculate DPS weights for the SCH, you can use SMN as a rough reference point as both are essentially dot-jobs.