I think we all want the lad to be a world beater, he's clearly got the raw talent, but there's something missing.
You absolutely cannot play him further back unless it's against poor opposition and Gana can do his covering. Not to mention he tends to take too many risks dribbling out from too deep. He's also and crucially for that position, got very a limited ability to tackle (Henderson blinder from last night aside!). His positional sense without the ball is also really poor, Koeman's pressing style is hugely let down by him (and Lukaku), just watch those two together with Barkley at 10. They both do the same thing in that they do their best to make it "look" like they're pressing and looking to put in a challenge but there's no real commitment there. It's probably part of the reason our midfield don't commit more to pressing further up the pitch with them as they'll be left all at sea. In fairness, Ross did at least run more than I've seen in a while last night.
It's such a shame with Barkley as he's got the classic "can do things with a ball few others can", but every time I watch him you can't help but feel that his brain is half a yard behind his feet. We moan about his decision making, I actually think he tries to make the right pass/dribble a lot of the time, sadly he's made the decision to do it a fraction late and his passes are either cut out, he's let the defender get too close and gets dispossessed etc...
Still want the lad to come good, but I just can't see him improving the parts of his game that he needs to. For me he doesn't have a quick enough footballing brain and in a team set up to press the opposition all over the pitch he will always be a weak link. If someone offered a silly amount of money I'd be in favour of taking it...