You’re best bet is to not cast RM unless necessary. This is because in M+ you’re using Chi Harmony (not Lotus Infusion) and you want the +50% healing bonus. What isn’t immediately obvious is hard casting RM (not getting it free from Rapid Diffusion) can decrease your overall healing.
The Chi Harmony +50% bonus only applies to the first 8s of a RM, regardless of whether you cast it manually, or apply it via Rapid Diffusion. The problem is RM hard casted lasts from 20s-60s (depending on talents, Rising Mist procs, thunder tea, etc…). Rapid Diffusion will not overwrite a longer duration RM. So you hard cast RM, then kick a few times pushing the timer up, those kicks will not proc rapid diffusion on the targets that need it if they already have a RM on them.
Rather cast EvM which will proc RM and get you all the bonuses (more healing, longer rolling HoT, longer duration of +healing bonus) and interacts with some very nice talents.
Use a WeakAura (or similar) to track Strength of the Black Ox (if you’re talented into it) and the Chi-Ji/Yulon insta-cast EvM. Between the two you should always have a quick EvM to toss on someone who might need quick triage. You can also ThunderTea an insta-cast one as well. Remember, you’re getting a lot more healing in all these scenarios. Strength of the Ox gives an AOE shield. EvM during Chi-Ji/Yulon cast an AOE hot and increases all healing on the targets by another 10%. ThunderTea EvM heals it’s entire amount upfront as well as over the hot given a big burst. There’s a LOT of layers to EvM healing.
If you have the Peer into Peace talent you can cast that and then blast insta-cast EvMs to cover a group with both EvMs and RMs and do some massive vivify healing.
For light healing, just kick/punch and toss the odd Strength of the Black Ox procs onto tank for free HPS. For single target focus toss EvM and then if necessary a vivify (but most of the time EvM will suffice) then back to kicking/punching.
AoE in lower keys use a CD. If you can stay in and melee use Chi-Ji. If you have to move use conduit (if you’re specced into it). If you’re forced out of range and/or there’s many targets lightning or Sheilun’s. If crap hits the fan, you have cocoon (off the GCD) and Revival.
In later keys where you need to ramp I use SooM into EvM. SooM + EvM + vivify is great for high single target damage like Anima Slash. The only real downsides to SooM spam is that you can go oom pretty quick (pretty much the only thing in the MW kit that can burn mana), you’re not dpsing (but keeping your tank alive is more important than you’re 5s of 400k dps), and you have to be stationary. It can also get clunky when the servers are slow, so use sparingly.