Putting "DRK" back in DRK

[Satarn]

You decreased blood gain rate by around 60-65% this is first.
Second, delirium in current form is gone.

The Blood isn't actually reduced - keep in mind that BW would have a much higher uptime and procs from all physical damage, not just gcds - including autos as well as Plunges and CnS whenever they line up. This, together with Blood gained from Living Shadow should result in about the same number of natural Bloodspillers.

You are right however on how changing Delirium would reduce the amount of Bloodspillers, which without increasing potency results in a loss of total BS potency per minute. This missing potency is being covered by Salted Earth basically becoming a 100% uptime dot, resulting in a lot of extra damage per minute, as well as some added potencies(namely, Salted Earth placement and CnS buff).

Third, oGCD strength has been nuked with nerf and got over 50% nerf in that department abyssal and cas gone (equivalent of 4% total dps)

Edge/Flood potency had to be reduced in order to account for higher amount of casts per minute, resulting from quicker MP regeneration. It's the same as how NIN's Bhavacakra and Hellfrog Medium were "nerfed" last patch, along with their resource costs being halved and NIN sure as hell isn't doing less dps than before.

Carve and Spit is not gone - in fact it's buffed by 50 potency - it's just gained an MP cost to add depth to DRK's MP economy. EoS potency is reduced to match the amount of casts with CnS - and LS - costs taken into account already, so nothing's lost there.

I did kind of forget about ogcd Abyssal though, but this could be easily compensated by splitting that potency into slight buffs to CnS, Salted Earth placement or even Living Shadow hits.

Fourth, you took away 5% bonus damage from buff

The 5% removed from Darkside is due to adding the 10% attack speed component. Increasing DRKs gcds per minute would not only benefit flat potency from said gcds, but also quicker generation of both Blood and MP. That said, Darkside damage bonus as well as tick potency on Salted Earth, are two numbers that would be the easiest to adjust in order to increase/reduce total dps, due to their full uptime nature and I'm fully expecting this to be necessary if any of this was to be implemented.

TL: DR: There's a lot of moving parts at play which have to be taken into account while analyzing any individual change and a synergistic design is more than the sum of it's parts.

[edit] Slap 90 extra potency onto CnS, 20 on Dark Arts and 20 on each hit of Living Shadow - there's your 200 pot/min Abyssal Drain, easy. Alternatively, if we're really lazy could just boost Salted Earth Tick by 10, but I'd rather not make dropping it too punishing.