Questions about dual-school spells

So what are the rules of these spells?
Why can abjurer learn Fireshield(red/blue)(Evocation,Alteration) Lower Resistance Spell Strike(Abjuration,Alteration)Melf's minute meteors(Evocation,Alteration), but not Wizard Eye(Divination,Alteration )Wraithform(Alteration,Illusion)?
Transmuter can't learn Lower Resistance Spell Strike(Abjuration,Alteration),
both Enchanter and Diviner can learn Wish(conjuration,invocation), both are banned from learning Limited Wish(Conjuration,Invocation)
Edit:Otiluke's Resilient Sphere is bugged in bgee,fixed in bg2ee.