Honestly, I still don't like magic checks, but that's another thing. A few of hte people on Skype agree with me. Magic needs more rolls than anything else, you need to roll two checks for every spell, spell check and save.
One suggestion I have is to rewrite spells so they all still do something on a successful save.
Whta you really need to work on is the rules text. We don't want to just create a patch, here, we want to create a sytsem. What you are doing is writing a list of small fixes. You need to start at the very bottom. Explain what a spell is. What a caster level is and what it does. What somatic, material and so on components are. How range and actions and saves work. And so on. Look at the SRD, you should more or less replicate the entire texts on magic in here.
I'm aware the concentration DCs are low. But honestly? Most of these are only revelant in the lowest levels. Should Archmage Elkhanzard the Mighty fail his magics because of a bit of rain? I Don't think so. Grappling and attacks are still in, and I did use CMB for that.