Chromatic goes with debuffing, but none of those is much related to curses or chance.
If you'd like another archetype take a peek at invoker. You don't have to take another one though, especially if you want a lot of hexes.
The only painful hex to lose of those 3 is the first one though. By 8th level you have 3 basic hexes, by 16th you have 3 advanced hexes. That's enough if you're not getting heavily into hexes.
Outer dragons are the obvious patron for BFC with imperial second best at that until higher levels. The other patrons seem to be about buffing (metallic) and sneaky stuff (esoteric). Or sucky blasters in the case of primal dragons.
The other archetypes aren't compatible because they change the familiar or the patron spells, or they just aren't very good. With the synergist counting as that when you try to mix it with wyrmwitch. I suppose if you spend 2-3 feats getting a familiar you could make it work.
Some of that expertise comes from having Archives of Nethys available. Still, if you're looking for a luck or chance based witch then you might consider ley line witch (especially if you prefer spontaneous casting) or maybe mirror witch, or of course the base, unarchetyped witch. It's not actually worse than its archetypes, unlike some classes.
For some reason there's no patron directly related to luck or chance. Deception, fate or space might be worth looking at though.
It looks to me as if the hoard acts like an arcane bond. & while it doesn't explicitly say that the draconic patron replaces the standard patron, I can't think what else you would be losing to gain the draconic patron.
The other thing I noticed is that no where in the archetype does it actually say that any ability replaces or alters patrons or patron spells, unlike other archetypes that lock witches into certain patrons. Instead, it just says that the witch selects one of the draconic patrons under an ability by a different name (Draconic Patronage). As written, does that imply the witch still has a choice of a standard patron as well? If so, that is an incredibly powerful choice.
Legacy of Dragons is one of the worst written books in Paizo history (can't call it worst edited because it doesn't seem to be (content) edited at all!). Seriously, the Fighter archetype say it replaces the bonus feats at 3rd and 5th level - apparently, not a single person who plays this game looked over what the writers handed in!
Yes, the Wyrmwith ability should say it alters the Patron Spells ability, but do you honestly believe the archetype grants a second patron without explicitly saying so?
The witch's hoard is basically an arcane bond you can't enchant, have to pay for and have to lug around with you everywhere, and is pretty easy to steal from, depending on your GM.
You realize that you can literally sleep on your money purse, right? If your GM constantly steals your money and/or expensive material components, I think you're having far worse problems than some Witch ability!
Seriously, you don't need to sleep on an actual pile of coins. You can get a sufficiently expensive diamond (which you can buy and sell it at the same cost) and "store" it in an orifice of your choice during the day. You could probably also wear underwear interwoven with mithral or something. It also doesn't actually have to be your money - you could totally use your party members' stuff.
None of these things should be necessary unless your GM is a jerk or you're playing in a gritty hardcore game.
A hoard is harder to steal than a familiar is to kill, the penalties for loosing it are way less, and it's significantly easier to replace. In addition, the bonded object ability is stronger then what a (normal) familiar grants. All that plus the easier learning of spells.
All in all, Wyrmwitch’s Hoard is an upgrade (especially since it's not really hard to get a familiar from a different source).
What is the difference between a Witch's spells known and spells stored by their familiar?
None, they're one and the same.
The familiar is more or less the Witchs spellbook. They are both mentioned as the familiar "store" the spells that the witch "knows". Its a clunky way of writing it, but thats Paizo in a nutshell, they could really do with learning how to "keyword" gamemechanics instead of reintroducing/reinventing it every single time.
I haven't read Legacy of Dragons, so I wasn't aware it was full of mistakes like that one, so I had to question it.
You can check out the Fighter archetype here (the d20pfsrd.com version is adjusted), and for extra fun, read the special section of this feat.
Is there any given reason why they're both pointed out in the Witch's text, then? My understanding was indeed that they were one in the same but it feels weird that they're both mentioned. Another editing/printing irregularity?
The "spells known" stuff for preprared casters is only in the class description because WoTC apparently though otherwise player's don't understand the difference between prepared and spontaneous casters. Thus they added it to the Wizard's 3.5 description, which was copied into the PF version, and then used as a blueprint for all prepared arcane casters.
On a side note, these two posts offer reason to hope that the issue will improve in PF2.
Basically, it's utterly irrelevant what spells a Witch "knows", as there is no class feature that cares about that. What's important are the spells stored in the familiar. Or in this case in your hoard, which means they must be somehow stored in your mind, as there's nothing preventing you from sleeping on a totally different hoard every night... yeah, it's a bit weird. When in doubt, ask your GM not to give you grief over what's more flavor than anything else.
Oh, and because I forgot to respond to it in my last post:
I looked at Chromatic and liked the list
You realize that seven of the nine spells are already on the Witch list, and thus these patron slots are utterly wasted, right?
WOW that is a poorly written archetype, you weren't kidding. It's easy to correct for players and DMs, of course, but still, wow.
In a way, this might be the single hardest to fix archetype in the game because while it's easy to make it work, it is absolutely impossible to deduct what the original intend was. Should the archetype replace the 2nd/4th level bonus feats, or the 4th/6th level bonus feats?* Should the archetype get the abilities at those level, or actually at 3rd/5th level (yes, that's possible, cf. Motunui Arsenal Chaplain)?
*) That does make quite a difference - if want Cornugon Smash and/or Shatter Defenses ASAP, replacing the 6th level feat is rather painful, if you want to play something that takes a few feats to work, loosing the 2nd level feat would hurt more.
Also, have I mentioned that the archetype grants Arcane Strike without a caster level, so the feats doesn't progress as written?
I just love the flavor of [Wyrmwitch's hoard]
I wholeheartedly agree - as I've said before, I consider Wyrmwitch to be the coolest archetype in all of Pathfinder. It's possible to make the archetype work despite the GM not being supportive, but that would probably take most of the fun out of it.
No worries on that here - my GM's cool. The whole group I play with likes to favor fun and flavor over just being a dick to our players and each other. Which probably shouldn't be as rare as it is, but I've read these message boards, so I'll count myself lucky.
I think that's actually the norm, you just never know. For instance, I made those suggestions just in case your GM was 'uncool' (or you were playing a more gritty game). It's also nice to know if the campaign puts you into a situation where you don't have access to your usual stuff.
On a note, mystic past life Samsaran is about the most powerful race option in the game, and Witch is a very strong class, so be sure not to overdo it (especially with the spell selection - I'd honestly advice against selectign Summoner spells), lest you tempt your GM to actually do something regarding your hoard.My idea for the archetype was to "fuel" the hoard with stuff collected from defeated enemies - you know, all magpie like - stuffing it into a Bag of Holding for transportation. Then, when the others unfold their bedrolls, you pour out your bag and make a bed out of the randum stuff you've, well, hoarded.
To elaborate a bit, what makes Mystic Past Life so powerful is that it allows the character to ignore some of the normally hardest to overcome limitations in the game. For instance, a Witch's spell list is significantly weaker than a Wizard's, to balance the super powerful Hex class feature.
Now, six spells aren't enough to make your list on par with a Wizard's, but if your grant some key spells the Witch's list is missing (Invisibility, Haste, Greater Invisibility, Permanency, Contingency, Time Stop, and Wish), the remaining gap grows pretty small. You're still missing the "you shall not pass" battlefield controll spells (pits and walls), and a bunch of other utility stuff, but most days, you won't notice much difference. For campaigns ending at mid levels, you could also use the Bard list to grab spells like Silence, Good Hope, Freedom of Movement, and Bard's Escape in addition to Haste and the Invisibilities.
Specially for the Wyrmwitch is also relevant that you can basically ignore it's main downside. Normally, the archetype's weakness is that you can't grab standout spells like Haste or Invisibility - well, know you can!
Probably even more powerful (depending on when your campaign ends) is using the Summoner's spell list to get spells like Haste, Greater Invisibility, Wall of Fire*, Overland Flight, (Greater) Teleport, Maze, and Dominate Monster at reduced spell levels, allowing you to cast those spells earlier than any other class in the game.
*) Normally a mediocre spell, the relatively cheap Lesser Metamagic Rod of Dazing turns it into a powerhouse.
I would rule the latter. It specifies spell.
RAW, it's the former - nothing says you can't do the "sleeplearning" for multiple spells simultaneously.