[Metaphor: ReFantazio] How chill is the platinum?

I just got done with outlaws and it wasn't that bad. Looking for a JRPG pallete cleanser. I've wanted to play this a ton, but OG persona 5 threw me off sometimes where I made 1 mistake and it would set me back hours.

1. Are there missables around every corner?

2. How bad is the superboss on the 2nd playthrough?

3. How are the grindy trophies?

4. Is it pretty casual overall?