1. My inclination is to pursue interventions for increasing automaticity in reading and calculating, rather than generic processing speed. There is more of a body of research for building academic fluency than for PS in isolation. Jim Wright has a number of resources for reading and fluency, including curriculum-based probes for assessing progress:
http://www.jimwrightonline.com/pdfdocs/brouge/rdngManual.PDFhttp://www.interventioncentral.org/response-to-intervention2. Happy to have helped.
3. Doesn't look like it made a difference which old WMI subtests were used in the index score, as they are all quite similar.
4. Again, it is quite challenging to find any evidence-based interventions for remediating cognitive processing weaknesses. More practical is accommodating it, and using his strengths to remediate any visual-spatial-related academic weaknesses that emerge along the way. It is possible that this cognitive process is another place where dyslexic or dysgraphic qualities are showing up. Accommodations would include monitoring his tipping point for being overwhelmed by complex or disorganized visual stimuli (or, in school, keeping it simple and non distracting). I'd also suggest visual frames and guides for reading and calculating (easy: take a sheet of paper or a bookmark, and screen off material that he is not working on right this minute. Helps with tracking, too.) I would keep an eye on how he does with geometry, when he gets there. This profile sometimes does much better with algebra than with geometry. He'll probably be better with the logic of proofs than with all the compass/protractor construction exercises so beloved in middle school geometry units.
5. This is where the action regarding visual spatial is most likely to be informative or useful. You could pursue OT eval through your pediatrician, but probably better through a psychologist. Except that your current evaluator doesn't seem to have made that recommendation. I don't know if you've received the full eval report yet; perhaps this and the question of dysgraphia will be addressed in it. If school is concerned, you could also ask their OT to evaluate him.
6. In addition to the cognitive information you already have, you would want achievement testing, specifically about his word-level reading skills using both real and nonsense words, oral (and maybe silent, too) reading fluency, and reading comprehension, preferably at both the sentence and multi-paragraph levels. It might also be helpful to have data on his phonological processing skills (phonological awareness--including phoneme manipulations, phonological memory--though that one will probably be normal to strong, based on his auditory WMI, and rapid automatized naming--might also be average to strong, since it won't involve fine motor speed).
You could have this evaluation conducted by someone like the psychologist you already have (but again, if they make no recommendation for further assessment for dyslexia or dysgraphia, as a result of the current eval, I would be a little less enthusiastic about asking them to continue), or seek out a referral for a neuropsychologist, through your pediatrician. Likewise, the school system can conduct a comprehensive psychoeducational eval, which usually covers all or most of these areas, at no cost to you. For anyone other than the psych who did the WISC-V, make sure you provide them with this recent testing, so they don't duplicate (and invalidate) testing. Who you have do the assessment depends a lot on whether you want the schools to do something, and what your relationships and trust levels with the various potential providers are.
