Hi Narthex50,
1. You should avoid checking everything and evaluate each item individually to ensure it’s not deleting something you wish to keep.
2. In the games section, it’s usually cleaning logs and caches. You should use the Analyze tool to test each entry.
3. I’m not quite sure what you’re asking here. If you’re not sure if you should delete something, it’s bets to err on the side of caution.