Agreed on Sirius, @Quim. In fact, I think he's one of JKR's more interesting characters rash, arrogant, a bully, traumatised, lonely, angry, confusing his role as Harry's godfather with his friendship with James, not entirely successful at hiding his secret desire for Harry to be expelled so that he can have company at Grimauld Place etc in a fairly 'good guys vs bad guys' universe. But he's more a personification of Harry's hopes and fears about his parents and the magical world than a fully-realised character, and as you say, he's not there a lot.
In fact, DS has been listening to audiobooks, and while I thought at first that I simply didn't like the voice Stephen Fry gave Sirius, it got me thinking about how he's often not very likeable. Which is hardly surprising for a man who's been wrongly imprisoned for years, and then been living on the run on scraps and rats as a dog, then alone in a hideous house stuffed with dark magic and a creepy elf, but, no, I wasn't weeping when he died, either.
I was interested in the death 'beyond the veil' stuff because it's so early 20thc occult in feel, and there's the suggestion the dead are contactable because they're apparently speaking beyond the arch -- but it never reappears, does it? (And I had all kinds of questions about the extent to which having had your portrait painted appears to give you a form of afterlife. but not being photographed...)