I don't have a whole lot to add overall (apart from my love of the actor) but why 'I'?
I can't recall if I've ever watched an interview with Bettany - but I have
read some, and from his comments, he always appears to be horsing around - the journalist reporting how comfortable he seems being interrogated.
I may be wrong, but does this not sound more like an 'E' trait?
Of course, he could just be very comfortable in his own skin (how much can you tell from just reading the words he says,
really?) I'm just curious as to why you immediately typed him as an 'I'.
Edit: I just realized you were basing your observations off a particular video

I'm currently at work, thus cannot watch it - but will do later to see if I concur.