I can't talk to Paladin Danse anymore after he decides to stay at Listening Post Bravo while doing Blind Betrayal. Will I still be able to max out the affinity and have him as a companion in the future or I won't be able to talk to him ever again?

He won't talk to you if you are enemies of the BoS. Also, after Blind Betrayal, you need to talk to Maxson first before coming back to him. After talking to Maxson, he should be available as a companion.

You can't get his companion perk anymore if you can't bring him along and max out his stats because it requires you to talk to him. Personally, it's the best companion perk in the game.