That 8% must have been frustrating. It seems crazy they would deny services like that (saying he needed 7 or below). OTOH rest assured you have plenty of time to figure everything out. You have years before his grades will even count for college applications. Just do your best and don't look too far ahead (and it sounds like you are very attentive and are doing a good job).
If you lived near here, you would find plenty of writing tutors/organization coaches. Also, all the private and better public schools I know here in NYC have special help in these areas (they seem such common areas of difficulty). These schools have so-called "achievement centers" for kids who struggle in exactly the areas you describe, and in many cases the kids get class credit for attending a couple days a week. One of my kids was getting C - grades just last semester and finally pulled up his grades under threat of having to drop an elective and sign up for the "achievement center." He is in high school, and the C - grades in high school are more damaging potentially (to a college application) than D or F grades in 6th grade (which the colleges will never even see, and would not care about anyway). I'm not losing any sleep over it though since in this child's case I think it has all been a great learning experience for him. He DID pull those grades up (way up) and never did have to set foot into the dreaded "achievement center." His grades fell last term because he bothered too little with assignments (lots of late and several missing homeworks and projects), and he also had simply taken on more than he could handle (in terms of extra-curricular and audited classes he would have been forbidden to take for credit because the load would have been deemed too heavy).
I wonder if they have some kind of achievement center or organization coach at your child's school? Maybe you can access that help? There MUST be other kids struggling with the same issues. Have you asked the school what they suggest?
If you think spelling and grammar are real problems for your son, I would get a tutor for these areas, but the rest might sort itself out with time (and you don't need to wait TOO long before seeking opinions or testing for possible LDs). But don't feel rushed, you do have lots of time to figure it all out (and so does your son for that matter).
By the way, I hope someone else can help you with answers to your question about IEPs for ADHD alone, etc. I mainly wanted to reassure you not to worry too much about the D and F grades. For boys I think they are not so uncommon -- maybe you could even consider it a "stage"?!
