Avie ... I adore Hugo Weaving, I have been somewhat in love with him since I was 13 and he was in a miniseries called Bodyline ... so I can only second Boromir's comments about him being a wonderful actor ( for an amazingly intelligent and sensitive performance look at Priscilla...).
However, if you separate the actor from the role I do agree with you in some respects ...in TTT particularly there was a slight "creepy dad" element that I found disturbing. While IMO, just about all the characters were demeaned in some respect by their film treatment ..(Boromir perhaps being an exception being more shown more sympathetically), I think Elrond's character suffered most. In the book he is so noble and puts himself last .. the film makes him rather selfish.
I thought it was quite clever casting .... he has the right colouring and those wonderful eyes, and although I dislike Liv Tyler,it looked plausible that she was his daughter (although he is no where near old enough in reality!), and I reckoned as a Half elf he might show more signs of aging than a full blood... and he looked really good in armour
*thud*.
One thing I will say for the film is that they do seem to have made an effort to make the families have a plausable resemblance although I am surprised they didn't make sean Bean lose the accent that blew the whole thing... but then he kept it even to play Macbeth on stage in London....