The Doctor bristling a bit at Bill calling him her grandfather
First, he has a very poor concept of how he appears to humans. Secondly, there's probably some very uncomfortable memories attached to that title because of Susan.
Third, the Doctor is irritated by the implication he looks old enough to be Bill's grandfather instead of father, but he's probably missing the fact he is not only white, but almost ashenly white, which might make that cover story fall apart a little.
Not necessarily. She could still pass it off by claiming to be the offspring of a mixed-race relationship.
Eliza was only able to restore Bill's housemates and not the others because she had such a terribly corrupted memory that she couldn't remember the others The Landlord had fed her. It's also because the previous tenants' Liquid Assets had been completely drained — that's why the Landlord was looking for another six in the first place.
It was a cut line, but Harry was supposed to be the grandson of Harry Sullivan, one of The Doctor's previous Companions. Now, he tends to really get angry to anyone threatening his Companions (which has often extended to the families of those Companions) and threatening kids. Congratulations, Landlord. You just managed to press both of those on a guy that makes Daleks run in terror, and in one of the more Good is Not Nice incarnations to boot.
