Thorsten Kinhöfer became a Bundesliga referee in 1997 and earned his FIFA badge in 2006 but really started internationally with a CL qualifier in 2007.
Probably too late to become a real WorldReferee...
He was a UEFA category 2 referee but was moved to 3 in 2011. Then cat 3 was renamed cat 2, so nothing happened.
In 2003 Thorsten Kinhöfer was also active in the Korean K-League., the Qatar Q-League and in Saoudi Arabia.
Internationally this referee has a rather high card average, see his palmares.