[Avodah] Sources for several wedding customs

[Ben Waxman]

A friend asked if anyone knows the sources of the following customs:

1) The custom that seems to have developed over the last 6 years or so (or
more?) of the bride and groom blessing their friends at the wedding
2) The custom of summoning the deceased to join the couple under the chupa.
(Someone told me it's from the Zohar. I can look that up but does anyone
know of another source?)
3) The custom of the groom wrapping the tallit around the bride after he
makes the shehechayanu on it. Someone told me it's a "Carlebach" thing (the
part where they go totally under the tallit, like hidden); I suspect there's
some Sephardi influence there as well.

Anyone have any source information about the above? Please write the group 
and cc  toby at wholefamily.com.

Thanks

Ben