Re: Idris, I've been doing some more reading. Quoting Neil Gaiman,

You know, in early drafts we learned a lot more about Idris, and she was imprisoned on the asteroid, and she didn’t become the TARDIS until about 20 minutes in. But it only got interesting once she became the TARDIS. So we moved that stuff up.

So much Auntie and Uncle etc backstory in my head and in previous scripts — and there was even a lot more that we shot. Adrian and Elizabeth were funny and creepy at the same time, and they had dialogue that indicated that normally the TARDISes when placed in human form say a few words then burn up and die: what our TARDIS did in Idris’s body was unheard of. But then, it was too long, so those scenes, along with many wonderful Uncle and Auntie lines, went away.

Wish I could get my hands on some of those earlier scripts!