In terms of importance vs all issues to me, mild.
I suspect this is more important to players who will be mainly playing Divinity : OS co-op. Outside of testing during the alpha/beta, my plan is to play Divinity : OS post-launch with a friend rather than solo. When playing solo, you can just switch to the appropriate character when needed (the one with the better attitude score). But when playing multiplayer, you have one character who can interact with NPCs and it's really important to have received credit for all the actions of your team.
Otherwise, it's like your only character never even did the quests.
