A couple questions came up while looking at some builds/archetypes. I'll keep them each separate for ease of readability.
1. The Ashiftah witch replaces their familiar with a veil. The veil has the ability to hold spells like a regular familiar, but can it learn spells like a familiar? Me and a few people had a disagreement about if it could learn new spells, reason being the text says it can only hold like a familiar.
2. The Seducer Witch says it uses charisma in place of intellect for all class features. We debated if the skills per level (not class skills) is a class feature or not. The line "Each level, your character gains a number of skill ranks dependent upon your class plus your Intelligence modifier." from page 86 of the CRB has led some people to say that it counts, since seducer witch has otherworldly allure which reads: "Otherworldly Allure: A seducer’s power comes from her allure. She uses her Charisma rather than her Intelligence score for the purpose of all class features and effects related to her witch class, such as bonus spells per day, the maximum spell level she can cast, and save DCs of her spells and hexes." Is there a concise answer?
3. The Enlightened Paladin at first level gains the confident defense class feature, allowing it to add its charisma to dexterity, then add it to AC. The scaled Fist Monk adds an untyped charisma bonus to AC, would these stack considering that one is a charisma bonus, and one is adding charisma to dex, then adding it to AC?
FAQ for reference.
1. Yes, it learns spells just as a familiar does. It functions the same as a familiar in that regard.
2. No. Skills per level is not a class feature, it is a base rule, and unless it's specified as being replaced by a class feature, feat, or other such thing ala "the CLASS NAME uses STAT to determine their bonus skill points per level instead of Int", similar to how Undead have a specific line they use charisma to determine their bonus HP because they lack a Con score.
3. Cheesy as it is, yes they stack. The paladin ability specifies it adds to your Dexterity Bonus, thus modifying your Dexterity Bonus, not being a Charisma Bonus in itself. The monk ability adds your Charisma Bonus to AC. They are also lost in different ways due to this difference. So it's a Dexterity Bonus boosted by a Charisma modifier, and a Charisma Bonus from the Scaled Fist monk archtype.
Keep in mind, all three of these options you've presented are from Player Companions. Paizo published but not technically Core (many Companion bits end up refined and put into future core publication. This can be seen with a number of the items from Adventurer's Armory being in Ultimate Equipment, while a number more were dropped, perhaps for balance reasons). As such, many of them don't consider each other when their abilities are put together.
For number 3...
Isn't the Enlightened Paladin technically a DEX bonus? The CHA bonus is being applied to the DEX bonus.
So, technically, they aren't adding to the same statistic.
I imagine most people would probably consider the ability to be +DEX and +CHA, but the +CHA acts the same as the +DEX (lost if flatfooted, for example) and would say they don't stack.
Alright, I appreciate the answers. Sad to see the general consensus is Seducer Witch doesn't get charisma to rank, but glad to see that the Ashiftah can get more spells.