So, all the male characters are now helpless! Good work there Klaus, this game is terribly unbalanced! I am writing it off, and I haven't even seen it yet!
If we were to add some real-world verisimilitude to this concept, I really don't see how this power source is worth it.
Sure, characters with the Marital Power Source live longer on average than characters with other Power Sources. But the loss of Charisma and Will (-2 to each), and the perpetual -3 penalty to all checks (due to lack of sleep if the Procreation Theme is also used), would likely ineffectualize the character compared to others.
Of course though, the +5 bonus for interactions with other PC's and NPC's that also have the Marital Power Source, can come in handy at times.
So, from a realism prespective, I think it's at best only even odds as to whether the Marital Power Source is more attractive than the Solo Power Source.
Warning: multiclassing when you have the Marital Power Source may result in negative experience, and possibly losing the character (or at least half the character sheet).