Thoughts:
1. Make sure the writing goals are spelled out concretely in terms of what he should be achieving and how it will be measured.

2. Yes, get all the breaks and other accommodations into the IEP. Sometimes they prefer to put these into a Behavior Plan (addendum but still legal)

3. Are there other things that weren't working for him that you want addressed? Our IEP includes social skills and participation goals very explicitly.

HTH,
DeeDee