Why would you take Lana out of the picture? She will be the one keeping his head from going underwater after his enevitable first loss and run towards unemployment. Heyman was shit on hard when Ryback came to him and the way it was played out was pretty played out. Axel was/is on life support still, and Cesaro is just positioned wrong. Cesaro could be a great Heyman guy, but it was how it was done that hurt him. Hell his deal now being "autoheel" is just hated by fans, who refuse to boo him.
Rusev vs Cena could be great, especially if Rusev could go over Cena at Fast Lane without an outside source before losing at WM, that would be a sweet rub for him still. How WWE handles it (with the Cena winning the belt announcement) is yet to be seen.
Ambrose over Rusev would be dogshit, so would Bryan. They should just stick with Cena, or let Ryback have his big win. I'm still confident it's Ryback taking the wind out of Rusev's sails, and I like that.