I have theory that he did love her in her first life, it was just she was such a bad person that he didn’t wanna accept and acknowledge his feelings cause of how she was back then, one of the tell tale signs that he did love her is that he never really apprehended her on her actions, he just let her do what she wants never reprimanding her or telling her off, and I also think that he could and can make her authority as an empress useless or be lessened if he wanted to but he just couldn’t, I think he felt some sort of guilt or its just that she has such high standing even he couldn’t do anything. Anyways this is just my theory, you can agree or disagree.
She is yes,but the prince is at fault too,knowing they already married but he still took that blue haired woman and get her pregnant too,he also spends more time to that blue haired girl than his own wife,I think the fl's feelings that time is valid.and I do have a hunch regarding that blue haired girl,maybe she intentionally seduce the prince for her to become empress,she plan to ruin their relationship from the start I think,but I'm still hoping she really a kind girl..
And to be honest I still not like the prince for her,maybe because of what happen to them in their past life,their relationship can fix if the prince try to properly communicate with her and explain everything,but he stayed quiet until the FL did something horrible to the blue haired girl....I just hope she ended up with other ml,not the prince...
I agree with you. I'm still turned off/dislike like the fact that he had a concubine but in the end, it's completely normal for royal family to take concubines in their setting. He didn't even treat her badly until FL tried to kill the concubine. Ultimately they were in a contract relationship and they both knew it. As a comment above said it, FL herself said that she mistook his respect for her for love, and then everything spiralled downwards. Honestly I feel like IF FL had not be poisoned to act so evil, then even if FL didn't act like her current "I don't like you crown prince" self, the two would probably have a good relationship.
It's not that he can't tolerate being rejected or anything (and hence being interested in FL) but more like as long as FL was a decent person/noble he would have liked her. By decent I mean not torturing her servants and maids etc.

Pls don’t forget that she was a very very bad person in her first life, so it’s pretty understandable if He didn’t love her then or atleast showed it. She was straight up an evil person, she was mistreating and abusing people left and right, using her authority to get away from it, so him not being affectionate isn’t that surprising honestly. The fact that everyone just ignored it and never tried correcting her behavior, people around her is also at fault for her becoming like that. She literally abused her brother his whole entire life and not once her father stopped or talked to her about what she was doing.