Reading through the comments I am having a tough time figuring out if this thread is still active, but I do have a few ideas.
Firstly, you ask what must be changed to follow some form of logic? As noted, magic usually isn't very logically, however I understand what you mean by this and to me it seems like an additional (9th) domain might be useful (since 7 doesn't seem to work as you mentioned in the comments) to ensure some sort of balance. That is, a rock-paper-scissors mechanic. The main reason to use an RPS mechanic is to make sure that no single ability, or any combination thereof, is head-and-shoulders better than the others. If this were the case, there would be no real reason to ever use the other spirits, or for that matter include them in your world, thus my suggestion to add a 9th.
A functioning rock-paper-scissors mechanic can only work with an odd number of features. The ability to bind multiple spirits complicates the system, but the combinatorics exist to sort the problem out. My initial suggestion to simplify things here would be to only allow 3 spirits at any given time. This works well as a multiple of 9, and still gives an 24-, 12-, 8-hour time span feature as you mentioned. 805
Should you decide to go that route and run into a specific problem developing a balanced scheme, that may make for an excellent follow-up question.
As far as which domains must be added to cover the whole spectrum of a human being? my initial thought was to add a creativity/ingenuity type category, but it would be hard to specify what exactly that might do, especially for the malevolent spirit. One idea that does seem to flow would be an Emotion category. The benevolent spirit would add empathy and the ability to relate to people, thus making them more likely to support your cause. The malevolent form would make you cold hearted and distant, which may be useful for making those "tough" decisions. Just an idea.
One other thing: the malevolent Appearance spirit doesn't seem fitting. Instead what if that spirit made you intimidating to others. People would be scared of you and thus less likely to oppose you, but also less likely to support your efforts. 140