Umm...
Paladin behaviour (i.e. children slaying, etc.) - I've had players who would happily slay everything in sight. Not while playing LG paladins, though.
Rules Lawyering (e.g. arguing over every last detail) - certainly players argue over rules, I do myself when I'm a player. As GM I give them short thrift. As player I try not to be too obnoxious.
Munchkinism (e.g. If I get X from book A and Y from book B...) - Yes, though I restrict game pretty much to core so it stays under control.
Finding Players - not a big problem now (living in London). As a child in Northern Ireland this could be a problem. Actually, even as a student, while I could find players, finding good players could be hard. But since everyine can access the Internet now, anyone living in an urban area should be able to find players.
I don't think any of the above are non-UK problems. There are some problems that do seem largely confined to the US, like hideously fat players taking up half the table space, but I don't think I've seen a hideously fat UK D&Der ever, even at GenConUK - and the portly bearded types there all seemed to be US RPGers who'd flown over for the Cons. I think this is a diet vs exercise thing - people in the UK, even if we eat rubbish, we still walk to get around.