I can help you out with this problem. I play at GVIII standard (My exam is actually this friday!) and I know this piece inside out. Where you mention the difficulty with rolling pieces, I assume that you mean the section that has the left hand going up and down in semi-quavers.
If it is, there is a solution. Make sure you use the fingering it suggests that you should use in the manuscript. If you can't, try playing the piece at a slower tempo and play one hand at a time so that the semi-quavers almost sound like quavers and slightly increase the tempo once your hands become comfortable and try to play both hands at different tempos and then try and go for it and play it at the suggested tempo. I used a fingering technique on those "rolling arpeggios".
With the left hand try playing the semi-quavers like this:
5 4/3 2 1 4/3 2 going up
&
1 2 3/4 1 2 4/3 going down
Try really hard on the Db Maj and C# min scales and and the arpeggios in legato once you have gotten really into that try and do some fingering exercises for the left hand that would mkae a firm even tone balance and a co-ordinated speed with the right hand.
I belive that thi is probably a GradeV piece and you should have no problem.
e-mail me back if you still having any trouble and I could help you Richiscoul