Thank you for the link. Although that link was the old api (i realized after overviewing the code for about 10min). But i found the apiv3 version.
The problem with videos sorted by viewcount/relevance seems to come from when mediaportal calls "QueryCategoryVideos" at line 685. This call order results by relevance (only 2 places do order by relevance. this call and the "QuerySearchVideos" call).
It could also be very nice, if you could add "New Videos" like in the old api. The activities.list can function the same as the subs feed from apiv2.