Well done - you've made the language much more restrained!
It just needs to be more concise.
1. I would omit the 10 words in the middle of "with the panel ...... as we left
". (No need for you to provide any explanation.)
3. After the first line, you need write no more than 5 words " - both our application and subsequent appeal
4-5. I'm afraid that challenging the panel's judgement, and discussing what a lay person might think, won't work. I suggest: "4. We have concerns about the criterion being applied by the panel ('whether a child will thrive')
(No point 5)
6 (now 5). Replace this with "Point 1 above was a clear breach of the Appeals Code.
7 (now 6). Replace "to ensure ......
" with "to ensure that all appellants are in a position to raise any concerns at the earliest opportunity
8 (now 7). Replace this with "With regard to other preferences, were the panel giving weight according to where schools had been ranked on the Common Application Form? If not, how could the panel justify the relevance of these questions when they should have been focusing solely on the particular appeal that they were hearing?
9 (now 8 ). Replace this with "Although we are confident that our son would thrive at the school, we have no wish to challenge the panel's judgement as such. However, there is no mention of any requirement to 'thrive' in paragraph 3.13(a)(i) of the Appeals Code. Surely the test is quite simply whether there is enough evidence of 'grammar school ability'?
Hope this helps.