First : Max shut off ecstacy hands because they are so power and he just gets them he so don't get time learn how to control their power that's why he turned off.
Second : Max dominated Ai in kissing because she doesn't have any experience and even if Max doesn't have any experience he still have biggining knowledge(just knowledge not experience) that enough for him to dominate her in kissing.
Third : Why he able to make her cum that fast only kissing because he possess H Tongue(upgraded version) which easily able to make virgin like Ai cum with only kissing.
Fourth : Max used Deep desire skill on her subconsciously then that was her desire to pick her like that in fairy tale where prince fallen in love with commoner girl and be with her. Ai cryed because she really take too seriously about Master-servent relationship like shown in anime she doesn't dare to say kaguya as friend cause of this even if she wanted to and she was in love with Max simple they grow up together and her feelings started to change from there.
Fifth : Ai think this was dream cause Old Max never would do that and show that kind of embarrassing face front of her because he was cultivated from childhood to hide his emotions as family being big family heir.
Sixth : Why Max only use Plane sex and not do anything else? Because it was Ai first time. Even though old Max used to convince himself thinking he not see as woman but deep down he do loved her. Old Max personality was like high Cold ceo in dog food novels.
Don't worry later he is not going to have just plain sex. It's going to be more juicy.