I think as far as Shelley and Sabin linking up in WWE, they'd get over as a face tag team but I'm not sure Vince would push them due to their long relationship with TNA. TNA is not the indies, they are direct competition as much as WWE does not think they are and pushing those two would lead to people eventually finding TNA.
Also, I don't think Vince is that interested in the tag division and quite frankly it's gotten so boring even with the new teams. Every match is exactly the same, it's as if the agents do not know how to do different tag team match finishes. A face win happens after the hot tag with both faces in the ring and a heel win occurs due to a roll up after interference from either a manager or the other member of the tag team.
As for the Kings of Wrestling, I'd keep them separated for now as both Ohno and Cesaro have the size and can get over by themselves and work good matches. If a time came for them to re-form then I wouldn't be opposed but both have had singles success on the indies and I'd like WWE to give them a shot individually first.