He started well, yes - against a completely abject Sunderland and, like you said, a poached goal against West Ham. Not so good the last five games.
Comparing them at International level is hardly fair, Okazaki comes from a country where football is far from the number one sport and much of the continental opposition is very poor. At least Nugent has taken to the field for England and scored - a lot of very good English players haven't achieved that.
As for the conspiracy theory - it's not that far fetched. I mean, he's not the first average Japanese player we've had is he?
Not one of your Uncle Nigel's best signings then!
... you should know by now Weller ... even though we were tracking the guy through both close seasons he won't be one of Nigel's signings unless he gets to be a proven success ... then he will have been of course!