Right off the bat: Proud Mode isn't recommended. There's no credos you're missing out on by playing Normal Mode over it. Difficulty as preference doesn't become a deterministic factor until KH2:FM
To add to this: there's no reason to stick to the original release when Final Mix is an option, unless you're wanting some absolutely vanilla perspective on things. Will not fault you if you prefer vanilla designs over Final Mix ones, but there's mods for that.
For information that's vague enough to only work when you've the context to understand it:
- The questions they ask pertain to rate of experience gained and where it plateaus. The threshold is always level 40.
- If you can't pick: take the shield. Only take the Rod either after your first playthrough, or if you're feeling ballsy.
- Just because you gain the ability to guard only after leveling up doesn't mean you're without defensive options. Almost every enemy has reaction states that interact with your common attack more than you realize.
- Bat Wakka his ball back. It's rude not to.
- No matter how many tricks Riku might get, his fighting style'll remain the same.
- You can beat every forced-to-lose combat encounter. You don't get anything but bragging rights via consumables.
- Don't head down when you get the ship.
- Your companions suck at managing potions. It'll pay off later to get used to menu cataloguing. Feel free to keep them stocked if you don't mind expending a fair bit more in the long run.
- The same as your basic attack, magic can also influence or manipulate reaction states out of enemies. Don't go thinking its only use is for healing.
- In a polka dot maze, check for a green bell.
There's other things to say, but it's better not to steal all the mystery. Hope you have fun with the game! If you're ever stuck, just rely on yourself for a bit longer, or ask in this thread before just perusing online!