1. in PvE cities or the harborage add an NPC or portal that transports you to a version of the zone you are in that is PvP enabled and in those zones allow travel to other factions zones freely using the wayshrines. the cities and wayshrines are safe zones but if you leave the area there is a 1.5 min cooldown before you can be protected again (to prevent abuse). as an incentive there should be a special additional mail sent after some kills that contains crafting mats and random upgrade mats up to blue.
2. add the same thing to cyrodiil for PvE but make you loose battle leveling and increase the mobs strength and add a lot of faction guards and random NPC warzones complete with siege that sometimes gets aimed at you

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3. add a similar thing for the imperial city sewers but the stones gained is halved,the retreat sigil is disabled, the multiplier disabled, and death makes you loose 50% of your stones.
At least be willing to let both sides have their fun especially since these will make it
OPTIONAL as in you want PvP IC you can do it, you want to PvP in wrothgar hell yes you want to complete your cyrodiil quests without some ass killing you you can do that to.
Before you start bitching and saying hell no consider this
you do not loose out on a single damn thing if this happens both sides gain something that has the potential to enhance their game experience