First of all, I heavily disagree with the thing that keeps popping up: Merging DWT and bahamut.
That merge achieves the following things:
- A significant loss in flexibility, for both your mobility windows and the use of bahamut on AoE situations.
- It's a plain nerf to dealing with downtime. It'd feel bad in fights with downtime and dungeons.
- Less mobility in DWT/bahamut due to the nature of demi-summons (and you'll have to use it in a bad spot because delaying means losing more later on)
- Complete inability to weave egi assaults, enkindle and devotion in DWT (because bahamut means no egi is out), forcing more R2 uses.
To your credit, you at least granted a method to spend aetherflow stacks in DWT/bahamut by tying akh morn to it.

Now I see you want to delete tri-disaster, but if that wasn't gone, it'd also mean there remains a heavy incentive to use it on cooldown even if a slight drift would work better, else you drop your dots and are forced into an extra hardcast.
I don't like it when the use of our tools is at the mercy of fight design, I miss being in control.

This rant aside, control is not the focus of your designs, so I'll look a bit at what you did intend:

Your aetherflow changes look a bit weird, giving rise to some counter-intuitive design, mainly fester increasing dot duration, while aetherflow is generated off hardcasting dots only if the duration < 10s. It very much depends on the exact potencies what you want to do here, but I can see an issue crop up where you'd never want to use fester or your aetherflow stacks (outside demis), as their mechanics fight each other. I'd suggest you completely remove this aspect of AF generation. The other method at aetherflow generation increases the gap between R3 and R2 due to it not generating from R2 (as far as I understand), is this mobility penalty intended?

Depending on the tuning of this aetherflow gain, you'd probably still be double weaving a lot. This also ties in to the penalty for using r2, and you'll have to weave in r2 or r4 to get your egi assaults off. Of course, it's to be expected that you always have enough R4 procs for your egi assaults after the opener, since there is a chain going from aetherflow generation to egi assault into R4, which if you save up for the next aetherflow can be used to weave the next (2) egi assaults, which would then grant you 1-2 more R4s to use.
With fester on a 20s charge timer and trances reducing their cooldowns, you'd have 3-4 uses of fester per minute depending on how much the reduction is, if it's a reset (grant 1 charge), you'll still be using 4 ogcds per minute on current aetherflow skills.
Depending on how much aetherflow procs you can get, the overall CPM can be both lower and higher than it is currently. If the proc rate is low enough, you might not even want to use any egi assaults (with egis out), and stock all of it for demi-summons because risking not getting maximum ahk morns and revelations out might not be worth the gain of the egi assault + r4, even if you'd end up losing a proc overall.

I suggest you take a look at how things would work out in the rotation, the ideas are interesting at least, but still needs a lot of thought. The changes are also quite ambitious so I'd not think a target within this expansion is reasonable, it'd be an expansion-level rework.