I am intrigued by this idea and also would like to address a couple of issues that have come up, if I may:
The books make it perfectly clear that in Britain, the only Muggle who knows about wizards is the Muggle Prime Minister (see Book: Half Blood Prince). Magical government does operate outside the law in every respect. Also, keep in mind, that if it was not such a closely guarded secret, Voldemort's rise would have had more opposition. For example, why didn't America step in (by the way, Salem Academy of Magic as possible spin off here)?
As for electronic devices, I agree that they should not be on school grounds. As for helping students with dyslexia, there are two views on this subject. One, can dyslexia be magically cured? If it can, why have to make the accomodations at all? Then two, if it cannot be cured, magical items such as glasses, magical quills that write words properly, or similar devices would be used. I think it would make for an interesting character development and roleplay in Diagon Alley for this character to find these items.
But I digress. I am definitely interested here. I'll keep an eye on this post. I have actually played on Harry Potter roleplays before and have enjoyed them immensely. Also, are you just looking for students or are you open to teachers as well? Either way, I am excited to see how this plays out. Also, if you are looking for another GM, I'd be happy to help with that as well. The HP-Verse is my passion, love it soo much.