1. When it comes to 100%, it usually seems to be, IF the game has a percentage counter, then you use that to determine "full completion". So 100% on the save file should be the decision there imo.

2. Low % is a little grayer for me. I'm leaning towards not collecting them, cause of the definition difference. Low % to me was always, beating the game with the minimum required items/stats/gear/etc to actually defeat the final boss. ALttP can't beat Ganon without a way to light the torches in the boss room for example. Rabi-Ribi is entirely able to be completed with just Ribbon and blue magic (and the amulets), so I feel that's how this category should be defined.

On the other hand we already can get Cocoa Bombs, food, or town member buffs in 0%, and eggs are essentially just extra currency. As long as the egg magic isn't collected a couple eggs along the way wouldn't really differ from what's already done.

I don't know that I have a cut decision either way for this one. Whatever the game counts as 0% is most likely the easiest option to verify, so I'd prolly put vote there.

3. All Town Members for the "beat Irisu" category, hands down. It's easily tracked, just pull up the member list at the end, and proof done. Requiring Fake Rita/Pandora seems extraneously arbitrary, and leaving an empty portrait slot for Keke Bunny at the end of the final fight equally so.