Yes, that one paragraph is about the sum total of the thermodynamics I know. It’s probably about all most people know. The Doctor, we are assured, knows much more. That he is capable of explaining it to Jackie, indicates that this Doctor is much more down to Earth and tolerant of his Human friends than he has bee in the past. Gone is the pseudo-science technobabble and instead we have a Doctor who is willing to explain things to those willing to listen. That Jackie is one of them is a sign that he is making headway with her. Jackie’s character was initially presented in the TV series as a bit dim, over-protective of Rose, and thoroughly hostile to The Doctor. But there were also hints that she was a caring person. I wanted to draw that out in these stories in which she slowly comes around to him. In this story she finally finds out the truth about The Doctor and Susan and handles it better than he expected. The fact that she and Susan get on is a start of her understanding him better.

As for The Doctor and David, that relationship was strained by a potential jealousy between the two of them over the twins. But The Doctor’s generosity in allowing himself to be a bone marrow donor to help David recover from his accident turns that relationship around.

Time Lords taste of honey. There isn’t really a bumper book of Time Lord facts. If there was, it might have been possible to look this information up. I DID genuinely find an online source that stated that Time Lords secrete sugar and salt and therefore taste of honey, but I have been unable to find it to confirm the source. In any case, the bit about soothing babies by letting them such a finger is my idea. It made for a good piece of conversation between The Doctor and Jackie and a funny response from Rose when she claims she never tried licking his fingers.

http://en.wikipedia.org/wiki/Thermodynamics