Well, it's just symptomatic of judging players at the age of 19-20; history is littered with examples of people thinking one player had more potential than another at that sort of age and things turning-out otherwise. Nothing case-specific, really.
Absolutely - to precisely what extent he's able to do that will determine whether and when he becomes a Test-standard player. Some people, however, seem to take it for granted it will happen. Sure, I hope it will, but it's far from a formality to my mind. I find it quite conceivable that Bopara will be unable to overcome all his faults, and thus could possibly continue to struggle all Test career against teams who can catch.
He's played lots of ODIs now, though, in a variety of positions, and not looked particularly well-suited to any of them. The only thing he's done well is pull games from the fire which have looked gone - demonstrating a remarkable cool head in adverse circumstances, which is why the assertion that he's mentally soft is so ridiculous. Bopara's problems in the longer game are based around his set-up and hitting the ball in the air too often; in the shorter they're based around his limitations and his inability to innovate.