I think it can begin to slip into racism when the terms culture and race are confused, and a
cultural label (sloppy time keeping, mechanistic obedience to orders, foreigner-hating, whatever) is applied to a
race. Some races are very diverse geographically, and cultures within them can therefore vary widely over distance. This conflation of culture and race is something you very clearly don't do, and in fact, go out of your way to differentiate between the two.
For me, though, a simple application of a cultural label to a race wouldn't be intrinsically racist anyway. It would be an anthropological confusion, of course, but a mistake on that level means little. For me, the problem lies in making moral judgements
on the basis of difference, and this difference could be in culture or race. Again, you haven't done this remotely.
So not racist, in my book, but certainly insightful!