Spell Caster House Rules

I had posted this idea a while back in the BX G+ community, but thought I would add it to the blog as that's where I have similar ideas for house rules. The idea is to make the acquiring of spells a bigger part of adventuring as well as giving spell casters a little more magical power by allowing for scroll creation.

• All magic-users and elves have a grimoire. This can be a your classic spell book, a long scroll, a tattooed pelt, scrimshawed bones, or any other means of recording written spells. Casting Detect Magic will distinguish a grimoire from a normal book or object.
• 1st level MU/Elves start with the following spells: Detect Magic, Read Magic, a 1st level spell of their choice, and one random 2nd level spell (a gift from their teacher for when the character is advanced enough to use it.)
• Clerics must choose a designated time of day (or night) in which they pray for their spells. Magic-users and Elves can only replenish a spent spell slot once per day and after a full night's worth of rest (8 hours+). If their rest is interrupted by anything more strenuous than taking a turn at keeping watch, the rest time resets. Unused spells are retained until cast or "traded out" for different ones.
• As the caster goes up in level, spell slots are gained but new spells are not learned automatically. They must be found to add to one's grimoire. Spells can be gained by three methods: spell research (X51), scrolls, another casters’ grimoire
• Copying spells (from another grimoire or scroll) to one’s own grimoire requires use of the Read Magic spell. Once the caster can read the new spell, he must spend the time and purchase special materials to add it to his personal grimoire. The original of the spell is consumed in the process. (This is why wizards typically don’t let other wizards copy directly from their grimoires!) It takes one full day’s work and 100 gp per level of the spell to transcribe it. This requires the caster’s full attention for the duration of the process.
• A magic-user or elf may create a magical scroll from a spell in his grimoire without destroying the original copy. (This is how spells are typically shared.) It takes one day and 500 gp per spell level to create a scroll. The scroll can be used to cast the spell or copy it, but it is consumed in either case. 
• A cleric may create spell scrolls for the same costs in time and money as magic-users or elves, but must prepare -but not cast- the spell for each day he is scribing the scroll.
• If a caster is desperate, he can cast an unprepared spell directly out his grimoire like a scroll, but the copy of the spell is destroyed in the process.