Heh, odd. All the things y'all cite as making The Lodger episode weak I thought were great character development points for this Doctor.
Basically this: The 11th Doctor has gone "native".
Compare to the previous Doctors. 9 pretty much had an axe to grind against any other species, especially the "stupid apes". 10 softened up near the end of his run but still had some pretty anti-social moments. Such as avoiding Christmas dinner in the season 3 Christmas special, amongst other little things (not to mention his huge "I am God!" moment in the Waters of Mars).
What The Lodger did was show to us something important about this Doctor: He's more "human" than his previous counterparts.
9 and 10 (except for maybe season 4) wouldn't have done frivolous things like play Soccer. And the earpod was a very good marker of this. Think back to season 2 with the introduction of the Cybermen, 10 comments of the earpods "You lot, you'd do anything for the latest upgrade!" And look what 11 is wearing...^_~ It even flashes the same way. XD
And the shower scene? Also character development. Apparently 11 was taking a very long time, which is a stereotype of someone a bit narcissistic. A character flaw which that scene helped drive home.
The tea I really can't comment on, but the headbutting...two things. 1. He was in a big rush, and 11 has proven to do some weird things the past Doctors haven't done before on nothing more than a whim. 2. He says he'll never do that again, something that I've only seen people see when they've just done something they knew would be painful/discomforting but did it anyway and greatly underestimated exactly "how" painful/discomforting it would be.