I agree that nationalistic feelings should be respected, which is why I try to wear the kilt in a becoming manner, and not just as a mix-n-match fashion fad. However, its easy to out-Scot the Scots themselves as far as tartans go. I know Scots who have multiple kilts and gladly wear one another's tartans (Hamish wrote about this as well) and have been told by Scots in the know that clan tartans are a touchy subject only at a clan gathering, which is a context in which I wholly agree great care should be taken not to offend clan sensibilities.

Those who feel awe for tradition (and yes, the 19th century was long enough ago to justify using that term in relation to clan tartans)should follow their instincts and wear non clan-tartan kilts. Those who feel less restricted by tradition can wear what they like, but its classier if they know and respect the feelings and history behind highland dress.

We must all follow our own inner light, don't ye think?