My main objection with Jean+Namor is that Emma's already been there.
Jean could certainly fill the matriarch role on an FF team with Sue missing at this point and time. Though I'm not keen on her automatically being paired up with Namor as well. Probably as I think he's a better ally than actual member of the Fantastic Four. If Jean has to be romantically linked to a teammate I'd rather it be Ben Grimm. Jean might like a good natured extremely loyal big sweet lug like the Thing considering her past with cheats and manipulators. Plus her telepathy is perfect for seeing behind the gruff exterior. As the FF is a family team the fourth member would have to be related to one of the team members maybe someone new like an unknown family member who's also a science expert. Say a new addition to the Storm family following in her relatives footsteps. Or introduce a 616 version of Karen Grant as Jean's cousin or long lost unknown sister, she could be a tech head working on a grant from Richards Foundation and drawn into a new FF adventure.
Also would like to see a crossover with Uncanny Avengers where Jean and Rogue compare and contrast their lives and careers since getting involved in the broader Marvel Universe.