I know this is thread resurrection, but I thought I'd point out a few things that I've had to dig around to find.
[spoiler]FROM THE ERRATA / FAQ THREAD (this is on the Paizo messageboards, from the author of Tome of Secrets, over several pages):
1) The Artificer doesn't seem to have a primary ability score. You could argue that it's intelligence, due to their focus on crafting and the craft skills, but really, it's never mentioned.
I envisioned them as a sort of Jack of All Trades -- but yes, with the concentration on Craft, Intelligence makes the most sense.
1b) Extending from that, what ability score does an artificer use when using her Weird Science abilities? Is it like a magic item, which uses the lowest possible DC? Do you have to rely on multiple ability scores (Wisdom/Charisma/Intelligence) depending on where you took the spell? Can you rely on a single attribute chosen at 1st level?
It's handled like a magic item, using the lowest possible DC.
2) Weird science items rely on the artificer's "caster level" when activating them, but is that set when you USE the item, or when the item is created?
The caster level is determined when the item is created, not when used.
3) Do artificers suffer any failure related consequences from working in armor heavier than light? If not, then why aren't they granted higher proficiencies? It seems that an artificer would have a lot to gain from dipping into a class like Fighter.
No, they don't suffer from failure-related consequences in armor -- but they weren't granted more proficiencies as a reflection of their academic nature. (So yes, an artificer/fighter combination would be a good one.)
4) You stated that you didn't want to have a core class reliant on spending GP to gain uses of their class abilities. I understand giving the characters free access to Master Craftsman and every magic item creation feat in the PHB, but they gain no discount to using any of them (also fine, but it makes me wonder). Plus, they gain metamagic feats and zero ability to utilize them beyond spending spell charges (again with the GP). What's the deal here? Why weren't artificers given the ability to utilize their metamagic feats in their weird science ability?
I felt that adding metamagic feats to weird science items would make them too overpowering (since they don't use charges, and the balancing factor of those feats are that they burn through multiple charges in use).
5) Many spells appear on multiple spell lists, sometimes at differing levels (the Ranger and Paladin jump to mind). Is it up to the DM to decide if this is ok, or should the player automatically use the lowest/highest version available?
The artificer can use a spell at whatever level it appears, even if it appears at a higher level on another list -- that's a reflection of their versitility.
ABOUT THE TABLE:
The part where you're making the mistake is in thinking that the "spell list" on the table is per day -- it isn't. That table entry is labeled Weird Science Inventions -- which means that at any given time, an Artificer may only have inventions that total the number of spell effects listed.
For example: A 4th level artificer may only invent Weird Science that emulate the effects of 3 different 1st level spells, and 1 2nd level spell. Whether that is 4 different inventions, or fewer inventions combining spell effects -- that's all they get. They cannot "swap out" spells -- what they invent is all they have. They cannot "mass produce" items by cranking out Cure Light devices every 4 hours, for example. They make one, and that's it.
If a device becomes unusable, they can build another (replicating the same effect), or invent a new one (choosing a different spell effect).
They do not expend GP to do this -- it's "MacGyvered" as Charles noted. (JWO note - I totally did not get the table as being the maximum number of gizmos / spells in a gizmo either)
Question about the artificer. Can they use wands as normal such as a wand of cure light or must they make a UMD roll every time? It says they have acess to divine and arcane spells up to 4th level. But from previous discussions earlier in this thread. It seems they just emulate the spells effect but they don't really know the spell. So can they use spell trigger items?
Yes, they can use spell trigger items. As the description on page 458 of the Pathfinder Core Book says, "This is the case even for a character who can't actually cast spells, such as a 3rd level Paladin." We figure if the spell-casting knowledge of the class allows a non-casting Paladin to use spell trigger items, the emulative knowledge of an artificer applies as well.
Can the artificer cast spells from scrolls? She can create scrolls at second level, but she can't read magic. Does this mean she needs to make a Use Magic Device check or that she can only use scrolls she has created herself?
Yes, she can use scrolls. A Use Magic Device check is required.
If she can cast a spell from scroll she didn't create, can she cast spells from a scroll beyond her current level (assuming the spell isn't higher than 4th level)? Can she cast spells from scrolls if she doesn't know what they do (i.e., if they haven't been Identified)?
As with any use of a scroll, an attempt to cast a spell of a higher level will require a caster level check (DC = spell's caster level +1). This would include spells of a higher level than the artificer would normally have access to.
The artificer could not cast from an unidentified scroll, since deciphering is required for activation. (as per page 490 of The Pathfinder Roleplaying Game).
The description under the feat Use Magic Device on page 109 of the Pathfinder Core Book says, "Decipher a Written Spell: This usage works just like deciphering a written spell with the Spellcraft skill, except that the DC is 5 points higher. Deciphering a written spell requires 1 minute of concentration." But the description of the Spellcraft skill on page 106 says, "This skill is also used to identify the properties of magic items in your possession through the use of spells such as detect magic and identify." neither of which the artificer can cast.
Deciphering with UMD 'works just like' deciphering with Spellcraft, not 'using the same requirements as' deciphering with Spellcraft. The spells are not a requirement for the UMD use.
[/spoiler]
So, the short of it: Weird Science uses the crappiest save DC possible for the item, so those non-buffing options really are only good for the first 2-3 levels, and you can put any spell from any list in there (hey, hey, here comes the L1 Haste machine). Also, that table is supposed to be the total number of inventions you can have with the stored spell at any given time. The author has clarified here that you have to break an item (presumably via UMD) to make another one: seems reasonable, if silly ("What are you doing with that death ray, Magnum?!" "I'm getting all the magic out of it so I can safely dismantle it." Rest of party looks at each other a little worried as Magnum continues to blast lightening into the sky...).
I also emailed the author about something specific I thought was missing: they no longer have trapfinding, and this was intentional.