I iTunes on Windows reasonably well. (I typed "just fine" at first, and that's not true. It has been a bit crashy and clearly a second-class citizen. But it works.)

iTunes feels this way on OS X Mountain Lion for me as well.

Why not? Renting movies via the iTunes store works fine here in The Netherlands... Haven't they added most European countries by now?

in France, the iTunes selection is pretty poor if you're looking for English content with subtitles. Most of the catalog is available dubbed in French - which is a pity, especially for TV Shows where dubbing is really poor.

The selection of iTunes movies in the Netherlands is a few months to half a year behind what you'd find on pirate bay though.

It's useless in Germany. It is just the same overdubbed stuff you can see on TV, several months too late.