This is a round-up of miscellaneous, possibly optional rules for a sorcerous magic system. Here are the other parts: Part I, Part II, Part III.
First is the topic of scrolls. Magic scrolls came originally from swords & sorcery literature, but they don't quite work the way they do in D&D. Scrolls eliminate the need to worry about power for the spell, because all the power arrangements have been made beforehand; the ink contains blood and/or rare ingredients, the incantation on the scroll calls upon spirits, demons or godlings and specifies what the reader is offering to seal the deal. Thus, they are a shortcut, like D&D scrolls. However, they are transferable; anyone may read a scroll, and whoever reads it is the one making the bargain with any entities named. All the scribe does is acquire blood and other ingredients for the ink. They can potentially be cheap to make.
When read, the GM rolls for or looks up the power cost of the spell. Then, the power actually being supplied by the ink is rolled, usually 2d3. The GM also rolls for the reaction(s) of the entities being bargained with. The person reading the scroll may not always know beforehand which entities will be called upon, how they typically behave, or what the incantation will offer them. The reader can break off at any point: if the scroll makes a pact with three different beings, the reader may stop before reading a Really Bad Name they recognize. However, any entities already invoked must still have reactions rolled, and any offers read are considered binding if that entity supplies the power, even if there isn't enough power for the spell. If the reader reads a name but skips the offer, the reaction roll is adjusted as if the reader called for aid without offering anything in exchange.
Clever scribes could actually use scrolls as traps, including all sorts of horrible bargains with crazy-powerful godlings in exchange for a simple Detect Magic spell, just to trick an enemy into calling upon a name they shouldn't call upon, or getting them to make a bargain they'd rather not keep.
Second is the topic of clerical magic. Healing and wards of protection pop up from time to time in swords & sorcery stories, so clerical magic exists, even if clerics themselves don't. A priest or holy man with an ability to heal or to drive away evil spirits is basically just another sorcerer, limited to a few low-level spells. The accepted power sources would be a few varieties of rare ingredients, perhaps with a threat to evil spirits (handled as a pact,) or an offer of later service to a "good" supernatural entity ("Heal thy servant, and I shall build a great shrine to you in this land!") How "good" the entity is can be determined by the GM.
I mentioned holy water in Part I. This is an easy to make "rare" ingredient, so it's actually not very rare at all. However, it provides at most 1 point of power to a spell; it's just a little something extra to couple with rarer ingredients or a generic plea to the spirits to allow healers a good chance to cast a simple healing. Actually making holy water requires first building (researching) a sanctified font, then "blessing" the water in the font (making a pact with nameless spirits without offering anything in return.) Not every batch of holy water will actually be holy. This shifts the game away from a reliance on "clerics" and makes clerical magic weak, but you could always ditch holy water entirely, if it doesn't seem weak enough.
There are also some issues with alignment, but that's probably worth its own post, since it would affect more than just sorcery.