Ragnarok.Jessikah said:
»Why can my wizard not say half cast a Fireball
Then they're not casting the spell and/or they didn't master it's power.
Ragnarok.Jessikah said:
»The game also doesn't want you to take just fire-elemental spells because there are 13 different damage types, with each one of them being resisted by certain creatures.
That sounds more like a personal problem. You can make characters as rigid of flexible as you like. Often times characters reflect more on the player. People don't always get into the idea of acting out a character.
Again, reflects on the character. Maybe they literally studied on the library of tomes to learn such a multitude of spells or maybe they've traversed far to learn them.
Ragnarok.Jessikah said:
»What if, as a wizard, I know it's smart to adventure with a library of knowledge from tons of different sources?
Some mages do that. They save a powerful spell as a sort of trump card or maybe you use it aggressively to raze towns and keep your enfeebling quietly to yourself.
Character development.
The players hand book is the rule book or guide book. It sets limitations on players so they don't go all crazy. It's like a subset of rules that are agreed upon. You can certainly use them like a rules lawyer to swap your spells around however you want. It could be part of who your character is, always in the lab tinkering away.
The rules aren't something to get frustrated about and you can certainly push them to their limits. The nature of the game is to encourage homebrewing as every adventure is supposed to be unique in it's own right. You can play really strategic campaigns like Risk. Those are cool, too. It just depends on the player group.