"You look Time Lord."

If House didn't try to kill them, the TARDIS's human body would not have been returned to the main console room and House would not have been destroyed; House did have an option even if the Doctor did not explicitly present it as such.

On the other hand, can you imagine any single other being as integral to the Doctor's identity as the TARDIS? I see him as being at his most ruthless in 'her' (if gender is at all relevant for an 11th dimensional being) defense.

As for the TARDIS, I suspect she had no scruples about killing House whatsoever, given what House did to so many of her 'sisters' and attempted to do to her. Does the TARDIS miss the other TARDIS's? What kind of a community, if any, did they have?

One interesting thing I saw mentioned in another review is that there's zero curiosity about or exploration of Idris-before-she-was-TARDIS in the episode; it's a horrific thing to happen to anyone, and a hole ripe for fans to fill in.

Just my two cents.