The simplest way is to use unlockallmaps before finishing the 3rd part of ch.2. Then you go to the new areas unlocked and do all the quests and finally you finish your normal path. That way you can do everything, however the story won't change and the alliance will be limited to what you chose initially. I'm not sure if the ending changes and if the game takes in account the fact that you ended all the edicts. You should be careful however because it's possible to accept quests from Bleden Mark too and if you go to him your alliance is considered broken and you'll be considered automatically on the anarchist path.
Wait wait! You say that simply unlocking all maps in stonesea will allow me to get the quests?
Because right now my problem is this: I can unlock the plainsgate map and get there. I can (using cheats) get my journal to list the "unlikely allies" quest as started. However, when I get to stone sea, I'm supposed to speak to an earthshaker contact there. The character is indeed there, but I can't speak to him (or her) and progress through the quest.
I can get the minor quests, such as those that starts directly in plainsgate, but since I can't progress on the main quest it is all pointless (I can't lift the edict).
Do you think that by unlocking all the extra areas in stone sea I can get directly in the cairn map and finish the quest?
I only care for the quest itself, I do not care if I can't recruit the earthshakers. I simply think that one should have the possibility to lift all edicts in each path, especially on the rebel one (you are supposed to be freeing them).