I've watched the interview again and you don't really get anything from it that you won't get from the film itself. The main themes are obvious and the discussion frequently returns to the sex scenes.

There was an amusing anecdote discussing the sex scene between Marco and his screen wife, Reygadas had to seek permission from her real life husband (who happens to be a high ranking police official) he was more than obliging to let his wife appear in the scenes as long as Reygadas guaranteed it would be simulated. 

Cheers Trev.