Oh, what a lovely little ficlet! It's so like Sherlock to have a specific slot for every important person in his life--Morarty might lump them all together, but I think to Sherlock the people that matter to him are just distinctly themselves, and being distinct would each need their own label. And of course he would never tell Lestrade he was waiting for that ring to come off, no matter how much he minded that it was still there.

(I also really can't see HoB happening before the Christmas of ASiB--possibly before Irene's rescue, but I can't see it being before defeating her. February or March, I'd have thought.)

ETA: In a recording of a live chat on the Guardian website, Mark and Steven say this about the timelines:

Mark Gatiss: 'Hound' at Christmas? What makes you say that? It's possible it takes place within the time frame of 'Scandal' as that lasts a year but...

Steven Moffat: Well I'd be interested in the time line theories, that's an old standby of Sherlock Holmes fans. We assumed they happened sequentially, but what do we know?

So I think you're quite right about the timeline!