I saw Ritchie play week in week out for Swindon 4 years ago (in the 3rd and 4th tiers of the English league!), and he struck me as good, but nothing special. That said, he's clearly come on, and deserves his place in our starting XI. The goal against Poland was magnificent, but he more or less cancelled it out by giving away that needless free-kick that led to the equaliser.
Agree that West Ham would be a better move than Man U/Chelsea. Like all players, he'd be better off somewhere where he gets regular games.
Oh, and no, he's not in any way Scottish. But, he plays for Scotland, so he's clearly of interest to us. I don't think he should be playing for us, but that's another debate.