As for wedding gifts. I was shocked when brides started registering their gift list at department stores. Aren't we supposed to pretend we don't expect gifts at all? Now some of them are specifically asking for cash! What next, asking for tickets at the door? They might just find that people don't care enough about watching them be the center of attention in their five thousand dollar dresses to even show up.
Most weddings here have a wishing well where people can put cash in envelopes into - usually they write i n a card and put money in it.
Many invitations have some wording saying there will be a wishing well at the reception
People can still give non- cash things if they want to - and you often see a couple of wrapped presents there as well
I dont think anybody has found people don't then care enough t o come - it is very standard practice here to do that now and has been for many years.
(not sure what you mean by "the center of attention" - of course the bride and groom are centre of attention at their wedding