The representation of witches also varies a lot in media, even more so than that of vampires; if we only compare the Wicked Witch of the West from Wizard of Oz to the Halliwell sisters from Charmed, they have pretty much nothing in common. That's why I don't want witches to come out in a GP like vampires did, even though I tend to prefer GPs over EPs, I feel a GP would be way too small to contain all the things I expect from witches.
Some witches live for hundreds of years with eternal youth, others are blessed with the same longevity, but do age physically, and still others live and age the same way as ordinary humans. Some witches have spectacular active powers like throwing fireballs and turning people into mice, others "only" have premonitions and/or sharpened senses, and all of those powers may or may not be used at will or require special conditions, tools, or rituals to work. So yeah... I doubt we'll get all these possibilities for our witches to choose from, even if they do come in an EP.
As for werewolves, I think they could actually work with a system similar to that of vampires.
Possible Strengths: Werewolf Speed / Strength, Power of the Moon, Alpha Material (may or may not include the ability to turn others into werewolves, if not, that could be a separate skill).
Possible Weaknesses: Silver Sensitivity, Fleas, Random Rage, Uncontrollable Transformations, Lone Wolf (unpopular in werewolf societies if I'm not mistaken, could be either an inability to find / stay in a pack or a problem with the alpha's authority).
I can't really think of that many, but to make up for that, and to differentiate them from vampires, the werewolf pack could introduce werewolf hunters (something I wish had already come with vampires), and that in turn could give werewolves additional unlockable perks to better defend themselves. Sharpened senses could be either a strength or a weakness depending on how you look at it, as it would help werewolves be more aware of everything happening around them, but at the same time give them stronger negative reactions to unpleasant sensory perceptions like a stinky environment or loud sounds. It would also be cool if sims could learn how to fully transform into a wolf, i.e. not just a very hairy human like in TS2, but an actual four-legged, controllable wolf that comes with special interactions not available to werewolves in other stages of their transformation.
