@ZOS_RichLambert @ZOS_BrianWheeler @Wrobel

Problems.

PvE players want to do IC unmolested.
PvP players want to kill anyone and everyone in IC.
PvE players refuse to enter IC while they can be ganked (unless essential which they hate).
PvP players get an empty IC as theres no one there to kill.
Some PvE players dont mind being ganked in a PvP zone while others do.
How do you keep everyone happy ?

The darkness falls concept doesnt work as;
a. You need emperor faction that only has access, but faction dominance and unbalanced population and time zones make this unfair.
b. Allowing 3 buff campaigns with one per faction makes the emperor access pointless as everyone faction has full time access.
c. The DLC issue is another problem. How can you deny access to people who paid for access ?
d. PvE players will not purchase IC DLC as they have better things to do then pay to be griefed (they want PvE).


Solution (Depending on how easy it is to faction lock Imperial City).

Switch between factions and PvP/PvE in a rota system that cycles over a reasonable timeframe.
I figure a 6 hour window to cycle - should give all the global playerbase time zones reasonable, equal and predictable access +-3 hours.
With this essential limitation I would therefore propose;
a. 1 Hour EP - PvE only
b. 1 Hour PvP
c. 1 Hour AD - PvE only
d. 1 Hour PvP
e. 1 Hour DC - PvE only
f. 1 Hour PvP

This should give enough time for each PvE faction to complete most if not all the PvE content.
{Not in one go obvisouly, but you can keep coming back. You will have to check if any quests exceed 1 hour}.
This allows PvE and PvP players fully guaranteed access to the DLC and gets around the paid DLC issue.
This allows each faction PvE player 16.6%+ game time to enter IC and farm goods / play content in an unmolested condition.
This allows PvP players 50%+ game time as IC was fundamentally offered as PvP content so merits the greatest chunk of game play.
Each of the 3 factions is locked out of cyrodiil IC for no more than 33.3% of total game time.
The emperorship and buff campaign issues are completely bypassed.
The Darkness falls concept of a dual PvP PvE content switch and zone is preserved.

NB.
You will have to warn all PvP factions and kick two factions when each faction enters their 1 hour faction PvE only phase.
You will have to warn the resident PvE faction when entering the all faction PvP phase.


Expected Result.

This should now remove the barrier that prevents PvE players buying IC.
This should increase the IC population considerably.
This should encourage some risk taking where the current resident faction PvE players may play beyond their PvE faction hour and into the PvP phase.
Just.....10....more...stones!
This should help immensely with crafters that want access, but are essentially PvE players that resent being ganked.

IC can now be completely isolated from Cyrodiil (standalone DLC with no PvE Population hit on Cyrodiil), shared pop caps with cyrodiil or offered as a cyrodiil overflow.
If IC is isolated from Cyrodiil you could consider reducing the group size limit to a more appropriate size, among other variables that could now work independently.
ie Tailor IC for small scale skirmish rather than large scale warfare.


Other thoughts...

You could phase and unphase EP/DC/AD into 1 hour phased faction isolated PvE and 1 hour unphased faction shared PvP, but that sounds complex and not without server phasing issues.
You could have the PvE PvP phasing switch as part of a temporal rift gameplay too - involving the amulet of kings, Akatosh, Molag Bal and dragon breaks.
Maybe play on the disappearance of the Dwemer and clockwork city in the process.
ie Make PvP PvE phasing, faction isolation and rotation - part of the fundamental gameplay itself.
Pitting PvE and PvP players against each other for server time...in their natural habitat.
ie players aren't kicked....merely elseweyr