I'd turn Sheamus heel post WM because I think:
1. It'd freshen him up
2. A WWE title feud with Sheamus backed by the Authority practically writes itself, what with Sheamus's super quick push to the top, being HHH's workout buddy for a bit, WM28 being the lowpoint of DB's career.
And I'd turn Cesaro face because fuck it he's already getting cheered by 90% of the audience so you may as well.