I like it a lot, it reminds me a little of my concept with less of a focus on pet positioning but a much more fleshed out downtime kit. Good work!

Some thoughts:

I think it's worth clarifying the situation with Aetherflow out of combat or at the start of a duty? I'm still convinced that blocking Aetherflow out of combat was a spiteful change that could have been made more reasonable if the SCH zoned/reset with full Aetherflow charges to compensate for it. Where do you think this sits with your concept?

On multiple dots, I'm of the mindset that SE deliberately trimmed everyone's dots down and moved away from dot centric classes to ease server load and make it harder to hit debuff limits in certain situations, so whilst I do like the thought of multiple dots again (Especially with offset durations) I don't think it's something that's likely to happen at this point. As an alternative, what about granting Bio increased potency when cast on a target that is fey marked instead of bringing back Miasma? Scourge's additional resource usage and duration difference is already a plenty decent improvement I think?

I'd expand on the above by having a thundercloud style effect on Bio's Fey Mark application chance so that when it procs, it leaves a short duration (Say 6 seconds?) debuff on the target that does additional damage if you refresh your dot on that target in that window. That alone will stop your dots always being refreshed at a content 30 second cadence, introducing some variance at all levels of play which is only a good thing if you ask me.

Ardor and Pain are good stuff. Same with Scourge and Meltdown (Especially if the range is fairly short). Bane's return is something I'll always be onside with although I'm not really sure about Toad?

Instead I wonder if it'd be more interesting to make Bane spread Fey Marks as well, then switch to having 2 AoEs, one having Ardor's bonuses and the other being regular filler. With Fey Mark's charges and short cooldown, you're like to be able to use Ardor 3 times in a trash pull. Shortening the crit buff to say 12-15 seconds would reward savvy spacing of Marks as well with a pretty tangible benefit.

Overall though, great work, it's a neat concept and has some real potential IMO.