It occurs to me:
* Paragon Caster & etc. are super powerful on fast casters. Not just ur-priest, but also Sublime Chord (which can pick off of the sorcerer and bard lists as well). For Sublime chord, it also gives much needed spell slots. I don't think you should change this, as these are really edge cases. Ur-Priest is already broken, and sublime chord is a pain to qualify for.
* Similarly, Paragon Fighting Style & etc. are super powerful, because you keep full IL, get additional schools, additional manuevers, but you don't fall behind too much if you don't take it every pick. For example, if you just spent 1/2 your picks (4) on being a martial character, you would still get +2 schools, +6 effective levels, +2 manuevers & +1 stance. Some of your custom schools are worth it all by themselves (Hello "Red Magic" or some of the Plain History manuevers).
* Paragon Spell --> pretty innocent, but bypassing caster level constraints can be great in a few rare conditions (Contingency comes to mind). This is actually a good thing ... makes an otherwise bland ability pretty cool!
Best,
David