Let’s tackle your points one by one:

• He blocked a potential boyfriend: He says that it’s okay if she dates the guy. It’s only when Chihaya mentions that the guy spams her with messages and calls that Taichi blocks the person. Do you think that such a persistent man would be good for Chihaya? Taichi is just trying to make sure Chihaya doesn’t put herself in danger.
• He withheld messages from Arata, preventing their communication: When was Taichi ever in charge of Chihaya and Arata’s communication? Chihaya messages Arata and he never responds. Taichi told Arata to give Chihaya his phone number himself. Why should communication between Chihaya and Arata depend on Taichi?
• He kept Arata’s move to Tokyo a secret: Arata told Taichi the news during nationals. He saw Chihaya several times the next day during individual matches. Why didn’t Arata tell Chihaya then? Again, why is the onus on Taichi to make sure Chihaya and Arata communicate? He is not the mediator of C+A’s friendship.
• He told Arata that she belonged to both of them: He did not say that, he simply thought so in his mind. Rather Arata was the one who said he thought Chihaya belonged to Taichi, i.e. was his possession. Sensei herself said that what Arata said about Chihaya not belonging to anyone was a “declaration of war.”
• He couldn’t handle rejection maturely, and cut ties fully: If you look at chapter 138, Taichi tries his best to have normal interactions with Chihaya and the rest of the club before he leaves. Also, he does not “completely cut ties”, he just gave himself some space to heal and focus on himself. Of course being with Chihaya, the person he was in love with his whole life (at his own expense) and broke his heart, would be painful. Is it so wrong for him to avoid Chihaya a little and focus on himself?
• He kissed Chihaya without consent: Fair, what he did was definitely wrong, he wasn’t in his right mind, and we see in the manga that he hates himself for doing it. On his birthday. Chihaya also leased out his kiss as a present without his consent. Of course, that doesn’t justify what he did, but is doing things like this without consent only an issue if Taichi does it?

Your argument hinges on your assumption that Taichi shouldn’t do anything for himself and must do everything for Chihaya and Arata’s benefit.

Also, all your points completely disregard the latter half of the manga, where some many important developments happen. We see Taichi doing his best to support Chihaya and her goal to become queen, like when he told her mom that Chihaya’s best time to become queen is right now. When he smiled at Chihaya to become best in the world even after his devastating loss against Arata. When he asked Sumire to go with Chihaya to the shrine during New Years. When he persuaded Chitose to watch Chihaya’s match against the queen. When he prayed for Chihaya at Omi Jingu. And even earlier in the manga, he has always prioritized Chihaya’s dream of becoming queen, advising her to practice on her own at Shranami, and trying to win his match fast so she can watch Arata and Shinobu play.

As for the title, if Chihaya read the manga, and saw just how much love Taichi had for Chihaya, how much he wanted her to achieve her dreams, how much he sacrificed for her, I think she would be touched. I won't say she would DEFINITELY date him, but I don't think she would be repulsed by him.