Sounds to me like your attorney has a good handle on your case which demonstrates how getting a disability decision is really a combination of medical evidence and law. So I think you should make sure you follow his advice.

The most important thing at this time is that the ALJ find you disabled BEFORE your date last insured. If you haven't worked since 8/04, your date last insured would probably be sometime in 2009, five years later. When you do have these exams, you should stress that your condition has been like this for at least the last two years or more. You may not get the onset date you want (2004), but it is more important that you get an onset date before your date last insured (anything before 2009).