Abilities?

[Alexander]

OK, three questions.

1) I'm missing several abilities and can't seem to find the items that teach them. (I don't have Firaga, Thundaga, or Blizzaga, for instance.) Also, I'm missing items that I need to synth in places like Black Mage Village--items that I've never even heard of. Do one-time-only places like Terra sell items/skills that you can't get anywhere else, because I'm starting to think that's the case.

Firaga, Blizzaga and Thundaga - You buy at Daguerreo/Esto Gaza ONLY IN DISC 3. And Terra's items can be bought at Daguerreo on Disc 4.
Ah some items from Black Mage Village Disc 4 are from side-qests, like Dragon's Claw.

2) How does Guardian Mog protect Eiko? And how does Gamble Defense work, and how effective is it?

Two questions that I wanna know the answer too.

3) How does Level Up work? I know that when one character is disabled at the end of the battle, the EXP/AP they would have gotten is instead split between the other characters. Does Level Up siphon off some of the other characters' EXP gain to give it to whoever has it equipped?

Level Up gives the character with it 33% more EXP, not altering others' EXP. The numbers don't change though, but yoou can easliy notice the extra EXP. And Ability Up gives you Double AP. Simple, huh?
On, and the AP isn't splitted when a character can't get it. It is same same, always. Only EXP is splitted.

I'd appreciate it if you guys could answer this, especially since I'm working on a new file and don't want to miss any exclusive equipment (again).

Well... I did my best XD