Poor old Blaidd!
There are a variety of opinions on the offerings issue. I'm not too offended by the biodegradeable variety myself, but I know there are a lot of people who just don't like stuff left around at sites.
As for vibrations, that's a strange one. There weren't any pile drivers in the area? Could be so many things I suppose. If in doubt, I like to blame the farmers.
:-)#
Kammer x