David
"we're too big and too heterogenous to ever have a unified ethnic and cultural heritage. " As the EU is also discovering. Maybe the US will subdivide one day?

"Scots dressed up as cowboys at the Creetown Country Music Festival" They're really Scots? Or of Scots ancestry?

"Would it be odd if a Scot who is of Indian descent decided to wear a sari to her wedding?" I doubt if it would happen beyond the first generation but time will tell. In the same way, a groom brought up in England of Scottish parents might well wear the kilt for his wedding but not further down the line - that's the usual experience. Most people in the UK have no knowledge of their origins beyond great grandparents.

"Scots dressed up as their Viking ancestors at Up-Helly-Aa" Shetlanders do this to show that they're NOT Scots. In other words, it's a political statement rather than a "heritage" celebration.

In the UK we really only do heritage if there's money in it from tourism etc. Which is sad, In general, as Scots, we're really not interested in clan chiefs (most would happily be rid of them), Highland games are essentially glorified fairs for the locals made possible by tourist money, we have very little knowledge of Scottish history or literature because political sensitivities inhibit their appearance in school curricula. Sorry, but that's the way it is for just now.

Alan