I agree! Your family will love it if you visit from the UK and so will the other guests. The likelihood is that you will be the centre of attention with your 'cute' accent. Definately take a present but pehaps something more British - something you could only get here.
And as for Carmel, we stayed there last year and the area is gorgeous. You can visit SF but also you must do the drive down Big Sur and stop at the restauarnt Nepenthe for a coffee or lunch overlooking the Pacific - heaven!
GO, you won't regret it!