I want to join the discussion
Before I comment your changes, I'll give you some general thoughts of mine about the idea of a Witch class.
- the stereotype can be already represented by the Sorcerer class, if you just remove the stupid "dragonblooded" bit; however it's perfectly fine to make a variant sorcerer and call it "Witch" if you want it to have a different spell list (with healing spells for example)
- I don't think the Sorcerer is weak, but I understand that you do and therefore I'll try to keep in mind that the result should be slightly better than the PHB class
- reducing the number of spells in the spell list does not make the class less powerful, it only reduces the differences between different witches, as long the known spells are the same amount; ditching a type of spell completely (such as teleportation) has indeed an overall effect, altho it's hard to weight it
- keep it simple: 99% of the times you can have a character do what you want with existing stuff, you don't need to introduce new rules (that is obviously part of the fun, but it's easier to deal with stuff already used

)
Merlion said:
Hit Die: d6
Skill Points: 4
Weapons/Armor: No armor. Wizard weapons.
Saves: Good Will, Poor Fort/Reflex
Two changes that I suppose they are on the line with the idea that a sorcerer would need a little boost. They are definitely ok, no one could argue that avg +1 hp/level or two more skills make a class overpowered...
It's good to keep in mind that with reduced proficiency, we are in debt of 1 feat with the Witch (used to be Simple Weapon Prof).
Merlion said:
Spells: Casts Arcane spells. Same as Sorcerer, accept one more spell known per spell level from 2nd on (for instance, a 4th level Witch learns 2 second level spells). Same spell-trade mechanic.
Again, here I suppose this change is to slightly boost the sorcerer-like spellcasting capabilities. One more spell known per spell level is definitely going to be useful, it's about 25% spells more. I repeat that please you shouldn't think this increase would make up for having less spells on the list!
Merlion said:
1st level: Familiar. As the sorcerer ability,but the familiar gains additional hit dice like a druid animal companion, using half the witch's level.
Is this actually a benefit?
Normally a familiar has HD equal to the master and half of his HP, so the avg 20th level sorcerer had a familiar with 20HD and (d4+Con)x20/2; assuming a Con +1 (IMXP it's normally higher, especially at level 20!) that means avg 35, but with your d6 it would actually be avg 45.
As animal companion it will have its base HP +6d8 (and would be treated as a creature with HD equal to its base +6). Before applying Con it means avg +24.
I don't see which is the reason beyond this change, is the purpose to make familiars more resistant in combat? The HD increase also brings some attack and save improvements, but not that much if you only use half level, however maybe you mean to make these stack with the ones used by a core familiar.
Mah, could be ok... you can also more simply allow a witch to either have a normal familiar as a wizard OR an animal companion as a druid of the same level.
Merlion said:
3rd level: Brew Potion for free
Absolutely yes if you mean to have the FEAT for free, absolutely not if you mean that she can brew potions without spending GP and XP. It may not be overpowered if you keep other restrictions (the time and the amount of potions you can keep around when adventuring

), but that is just unfair for everyone else...
If you want the Witch to be a better brewer than everyone else, consider other possibilities (there's a master alchemist in FR to steal ideas from), among which I think these would work very well:
- grant the feat at 1st level (so that every Witch has it since the start, unlike anyone else around)
- let the witch brew multiple doses of the same potion at once: instead of 1 potion/day limit, use the same limit as wondrous items (1 day per 1000gp worth of the total potion); it's still best to allow this only if the Witch prepares multiple doses of the SAME spell, and it also fits with flavor... easier to imagine her with one big cauldron rather than brewing different stuff at the same time
- let the witch use Brew Potions for spells over 3rd level: this is definitely more powerful, so it could be best to let her pay for it by taking e.g. a feat to extend BP up to level 6, and another to extend up to level 9
Merlion said:
Bonus Feats: 5th, 10th, 15th, 20th, drawn from Item Creation, Spell Focus and Spell Penetration feats.
Still boosting up... all those bonuses are fine but they are getting many. It's up to you to see when it becomes too much, the drawback is only that the class may become too attractive to actually choose wizard...
Merlion said:
9th level: Witch’s Curse/Boon
13th level: at 13th level, the Witch may lay a Geas as the spell upon a single creature.
I don't think it's a good idea. Definitely fit the flavor, but why don't you just add the Bestow Curse and Remove Curse spells to the list? You also already have the Geas spells, what's the point with this ability?
If your point is to make the curses more versatile, just expand the spell, which by the way it says itself that the DM can approve variant curses.
If your point is to make the curse easier, for example making it a supernatural ability, that really only makes a difference in combat and not always.
If your point is to force that EVERY witch knows to cast a curse or a geas, I don't think it's a lovely idea... those could simply be very popular spells among witches, just as mage armor and magic missile are popular among wizards, but that doesn't mean it's a good idea to force all wizards to know them.
Otherwise, what was your point?
Obviously if you're just looking for the fun of writing down a new mechanic for curses in general, well that's ok...
Merlion said:
It's very fine as you did. Remember that a trick to make a new spell list very unique is to slightly increase/decrease the level of a few spells, but don't lower it more than 1 and be careful... but I think you have used this in the list (for example you used Druid levels for the Cure spells).
Obviously if I had to do the same list I would have done something slightly different because I probably have a different mental image of witches, which doesn't make my list better or worse

.
You probably aren't going to change it but these are core spells that I would have added also:
Unseen Servant
Disguise Self
Silent Image
Ventriloquism
Summon Swarm
Wispering Wind
Hideous Laughter
Blight
Veil
Simulacrum
Trap the Soul