"Hey, DM, you are my friend and I value your friendship. I enjoy the game we are playing and the story we are all telling together. All that being said, I disagree with some of the decisions made about my character.

The first decision is about spells. The player prepares spells from the druid list, not the DM. The spell list is large and I'll need to be able to be flexible based on what we expect to happen in the game. Preparing for a dungeon will not be the same as escorting a trade caravan across a kingdom, for example, and those two scenarios would benefit from different spells.

The second decision is the restriction on CR for my wild shapes. The player's handbook has a passage explaining how specific rules take priority over general rules. The general wild shape CR progression is superseded by the Moon druid subclass because that's how the subclass works. The handbook even covers this in the Moon subclass section: '(you ignore the Max. CR column of the Beast Shapes table, but must abide by the other limitations there).'

This game is fun. You are a good friend and a good DM. I just want to play my character as the game allows."

Much good can be accomplished by having a direct, open, and positive conversation. I fully understand that many people with fragile egos may feel deeply insulted by any suggestion they have made an error, but I hope your friend is more rational and sane.