Ironically, the parts I enjoy the most about this VN is when all the guys get together to play tennis. Although, personally, If I had any sort of influence on the story during its development, I would've made Eric the number one player on the team (a little better than Spencer, without reducing Spencer's skill level or drive to go pro), but make him have less desire than Spencer to make a professional career out of it.
Not only do I think that would be nice for Eric to have as an accomplishment from the get-go (or one that isn't earned through the association of the in-route love interest you picked, anyway), but I am also of the opinion it would help Spencer's character out a little, too, by removing his ONLY disparaging personality traits, that being how his ego cannot let anyone be better than him at the things he does and his tendencies to be an asshole on the court by having someone there to keep him in check.