Hi, I did the Etude in A and found the RH arpeggios really hard to get up to speed accurately, but I managed it in the end. I have the same prob. being left handed, my natural tendency is to thump out the bass as this is my dominant hand. However, after years of tedious practise, I now can control my left hand much more than the right, and can achieve a good balance.
My advice, listen very carefully to yourself, and work through sections of the piece varying the dynamics in both hands (i.e. LH piano, RH piano, then LH forte, RH piano, then LH piano, RH forte) until you can play really sensitively. It's also a matter of coordination, and so once you master the volume in each hand, work on "hearing" the balance until you are happy. Hope this help, soz if it's a tad confusing!