As of now, some video settings aren't implemented yet. You might notice it when you click into "Video Settings" and see the items marked with an asterisk. These are the settings that aren't fixed or implemented in the game yet. As far as when the developers are going to implement this, maybe after the open beta of the game. Right now, things are a bit patchy and laggy because the game isn't completed yet. Don't worry though, it will just take a couple of months more before these changes can be implemented.
I think that you can't change them. Well, none of us can change the video setting. It is the rule made by the developers and you can't change that. You need to wait until the set of new setting comes in the game. They will surely add the option of changing the video settings.
Video settings are a bit peculiar for Gigantic. Can they be changed? I mean, can they change after they've been set for the game? Gigantic is strange....
Since they are peculiar with Gigantic there won't be any success trying to change the settings. The developers may have to be contacted.
You posted this a long time ago. I think by now the game has been updated or upgraded to enable video settings.