These are excellent questions, and in the next few days I suspect you can get answers from folks on the board who are familiar with Accutane vs. Soriatane. Welcome to the board, we're glad to have you here.
So you know, many of us were off at the national conference from July 5-7th and only a few of us live close enough to the conference to have arrived home already. In the mean time, consider speaking with F.I.R.S.T. about retinoid issues. Their site is located at www.scalyskin.org
and they can send you some wonderful information.