Tai definitely seems to be into Touma even if he himself doesn't realize it and there are signs of it as far back as chapter 1, like when he asked Futaba why she liked Touma and got pissed off when he realized that her motives were genuine and not some superficial reasons like him being good at sports. At the time it seems like it is about him being jealous because he likes her, but as it becomes clearer that he sees her as a friend then the explanation that he was jealous over Touma becomes more plausible
I thought that Seiya was really cool this chapter, he didn't blame Taichi despite his actions being the cause Touma being injured. Plus wanted him to stay in touch, these are the actions of a mature adult