"Flatline" is the ninth episode of the eighth series of the British science fiction television programme "Doctor Who", written by Jamie Mathieson, and directed by Douglas Mackinnon. The episode stars Peter Capaldi and Jenna Coleman, with Joivan Wade and Christopher Fairbank guest starring. The episode received critical acclaim, with particular praise directed at Coleman's performance.
"Flatline" featured at least two guest appearances by performers who were not regular cast members
A: Yes

Sheree Victoria Murphy (born 22 August 1975) is an English actress and television presenter, best known for her roles as Tricia Dingle in the ITV soap opera "Emmerdale", Eva Strong in the Channel 4 soap opera "Hollyoaks" and Dakota Davies in the Australian soap opera "Neighbours".
Sheree Victoria Murphy still lives in England.
A: It's impossible to say

Cougar Town is an American television sitcom that ran for 102 episodes over six seasons, from September 23, 2009 until March 31, 2015. The first three seasons aired on ABC, with the series moving to TBS for the final three seasons. The pilot episode was broadcast after "Modern Family". ABC officially gave the series a full season pickup on October 8, 2009.
Cougar Town ran for about 7 years
A:
No