So I have had danse following me for a really long time trying to max out his affinity since you don't have access to him after the end of the game, but he refuses to like me enough to run away so I can have his quest. I haven't done anything he didn't like (dislike=reload last save) and I have made preston and codsworth idolize me while modding armor and weapons just by them being in sanctuary (and codsworth and I weren't even in good standing when I started doing this), but dance who loves both of those things and is actually my companion doesn't seem to be progressing at all. What am I doing wrong?

From the Fallout wiki entry on Danse:

• He likes it whenever the player character enters power armor.
• He likes it whenever the player character boards a vertibird they are called in.
• He likes it when the player character offer to help settlers for the Minutemen.
• He likes it when the player character chooses the 'reasonable' dialogue options.
• He loves it when the player character spares him during the quest Blind Betrayal.
• He loves it when the Sole Survivor does anything negative towards super mutants, such as convincing Virgil he needs to die.
• He loves when the Sole Survivor shows any kind of dedication to the Brotherhood of Steel in dialogue.
• He loves it when weapons, armor, or power armor upgrades are crafted.