part two
So:
Familiars cover the animals which do tricks and tasks, including guarding and attacking. They are material, and can be fought and detected as normal. They follow the mages commands explicitly, and to the extent that they can understand it. Roughly, I'd have the size be skill^2, , and the intelligence be skill x2. Each animal would count towards some sort of stuff limit. How you get them is for later, I would see one way as being chargen benefits.
Bound spirits are similar, but magical (thus invisible) ways to get things done. Stormbringer/Elric (Chaosium, tm) had some very cool rules about magic defined as spirits, which are worth stealing. My first pass is that a spirit is summoned (more on that later) as a disembodied characteristic: thus a spirit of strength, a spirit of endurance, a spirit of intelligence. The spirit would have all characteristics equal to the magic skill, except for their type, which would be a value of skill^2 (possibly skill +1^2 ? or should the low level spirits be VERY weak ?). What they can do would be derived from their type. Some examples: A STR spirit would specialize in brute force, and fighting; pretty basic. ; END spirit would reenvigorate and protect against damage. imagine a big invisible bag of ablative hit points. basically, if you're starving or drowning or being pounded, the damage comes off the spirit first. Thus water breathing is obtained by being able to avoid drowning damage for a while. DEX spirits are all about movement...add to your speed, or do very lightweight messenger duty at high speed. etc etc. Bound spirits count toward you stuffage limit, as animals, but more so.
Higher level spirits (demons ? Do we need to have a taxonomy ? They did in period, but so does D&D,) could perhaps manifest physically, and have varied stats . I'd suggest either combining spirits (say, merging a spirit of STR and a spirit of END into one for a better bodyguard); alternately, have a main stat as before, and a pool to devide up as the mage wishes: mage -3 creates demon of STR (9) with 9 stat points to add to the other char values which start at 3.
Some mechanism for manifesting may be needed. Perhaps they become physical when they interact physically.
Mesmerism (yes, I know it's a vast and terrible anachronism) would be similar to telepathy with an emphasis on domination, but with a VERY obvious effect: basic roll to Mesmerize someone to various levels based on skill. say, mild influence at 1 up to dominate (zombify) at 5. Duration could be a squared function here, with lesser effects having longer units.
Potions, charms,and curses later- feel free to chime in/critique !